Anti-pdl1 antibodies, activatable anti-pdl1 antibodies, and methods of use thereof

ABSTRACT

The invention relates generally to antibodies that bind programmed death ligand 1 (PDL1), activatable antibodies that specifically bind to PDL1 and methods of making and using these anti-PDL1 antibodies and anti-PDL1 activatable antibodies in a variety of therapeutic, diagnostic and prophylactic indications.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/133,231, filed Mar. 13, 2015; U.S. Provisional Application No.62/139,596, filed Mar. 27, 2015; and U.S. Provisional Application No.62/218,883, filed Sep. 15, 2015; the contents of each of which areincorporated herein by reference in their entirety.

INCORPORATION BY REFERENCE OF SEQUENCE LISTING

The contents of the text file named “CYTM038002US_ST25.txt”, which wascreated on Jun. 27, 2016 and is 785 KB in size, are hereby incorporatedby reference in their entirety.

FIELD OF THE INVENTION

The invention relates generally to antibodies that bind programmed deathligand 1 (PDL1), activatable antibodies that specifically bind to PDL1and methods of making and using these anti-PDL1 antibodies and anti-PDL1activatable antibodies in a variety of therapeutic, diagnostic andprophylactic indications.

BACKGROUND OF THE INVENTION

Antibody-based therapies have proven effective treatments for severaldiseases but in some cases, toxicities due to broad target expressionhave limited their therapeutic effectiveness. In addition,antibody-based therapeutics have exhibited other limitations such asrapid clearance from the circulation following administration.

In the realm of small molecule therapeutics, strategies have beendeveloped to provide prodrugs of an active chemical entity. Suchprodrugs are administered in a relatively inactive (or significantlyless active) form. Once administered, the prodrug is metabolized in vivointo the active compound. Such prodrug strategies can provide forincreased selectivity of the drug for its intended target and for areduction of adverse effects.

Accordingly, there is a continued need in the field of antibody-basedtherapeutics for antibodies that mimic the desirable characteristics ofthe small molecule prodrug.

SUMMARY OF THE INVENTION

The disclosure provides antibodies or antigen-binding fragments thereofthat specifically bind programmed death ligand 1 (PDL1), also known asPD-L1, CD274, B7 homolog 1 and/or B7-H1. The use of the term “PDL1” isintended to cover any variation thereof, such as, by way of non-limitingexample, PD-L1 and/or PDL-1, all variations are used hereininterchangeably.

In some embodiments, the antibody includes an antibody orantigen-binding fragment thereof that specifically binds PDL1. In someembodiments, the antibody or antigen binding fragment thereof that bindsPDL1 is a monoclonal antibody, domain antibody, single chain, Fabfragment, a F(ab′)₂ fragment, a scFv, a scAb, a dAb, a single domainheavy chain antibody, or a single domain light chain antibody. In someembodiments, such an antibody or antigen binding fragment thereof thatbinds PDL1 is a mouse, other rodent, chimeric, humanized or fully humanmonoclonal antibody.

In some embodiments, the antibody is an isolated antibody or antigenbinding fragment thereof (AB) that specifically binds to mammalian PDL1,wherein the AB has one or more of the following characteristics: (a) theAB specifically binds to human PDL1 and murine PDL1; (b) the ABspecifically binds to human PDL1 and cynomolgus monkey PDL1; (c) the ABspecifically binds to human PDL1, murine PDL1, and cynomolgus monkeyPDL1; (d) the AB inhibits binding of human B7-1 and human PD1 to humanPDL1 with an EC₅₀ value less than 10 nM; (e) the AB inhibits binding ofmurine B7-1 and murine PD1 to murine PDL1 with an EC₅₀ value less than10 nM; and (f) the AB inhibits binding of cynomolgus monkey B7-1 andcynomolgus monkey PD1 to cynomolgus monkey PDL1 with an EC₅₀ value lessthan 10 nM.

In some embodiments, the antibody or antigen binding fragment thereofspecifically binds to the mammalian PDL1 with a dissociation constant isless than or equal to 0.01 nM, less than or equal to 0.05 nM, less thanor equal to 0.1 nM, less than or equal to 0.2 nM, less than or equal to0.3 nM, less than or equal to 0.4 nM, less than or equal to 0.5 nM, lessthan or equal to 0.75 nM, and less than or equal to 1 nM.

In some embodiments, the antibody or antigen binding fragment thereofspecifically binds to the mammalian PDL1 with a dissociation constant inthe range of 0.01 nM to 1 nM, 0.05 nM to 1 nM, 0.1 nM to 1 nM, 0.2 nM to1 nM, 0.3 nM to 1 nM, 0.4 nM to 1 nM, 0.5 nM to 1 nM, 0.75 nM to 1 nM,0.01 nM to 0.75 nM, 0.05 nM to 0.75 nM, 0.1 nM to 0.75 nM, 0.2 nM to0.75 nM, 0.3 nM to 0.75 nM, 0.4 nM to 0.75 nM, 0.5 nM to 0.75 nM, 0.01nM to 0.5 nM, 0.05 nM to 0.5 nM, 0.1 nM to 0.5 nM, 0.2 nM to 0.5 nM, 0.3nM to 0.5 nM, 0.4 nM to 0.5 nM, 0.01 nM to 0.4 nM, 0.05 nM to 0.4 nM,0.1 nM to 0.4 nM, 0.2 nM to 0.4 nM, 0.3 nM to 0.4 nM, 0.01 nM to 0.3 nM,0.05 nM to 0.3 nM, 0.1 nM to 0.3 nM, 0.2 nM to 0.3 nM, 0.01 nM to 0.2nM, 0.05 nM to 0.2 nM, 0.1 nM to 0.2 nM, 0.01 nM to 0.1 nM, 0.05 nM to0.1 nM, or 0.01 nM to 0.05 nM.

In some embodiments, the mammalian PDL1 is selected from the groupconsisting of a human PDL1, a murine PDL1, a rat PDL1, and a cynomolgusmonkey PDL1.

In some embodiments, the antibody or antigen binding fragment thereofspecifically binds to human PDL1, murine PDL1 or cynomolgus monkey PDL1with a dissociation constant of less than 1 nM.

In some embodiments, the mammalian PDL1 is a human PDL1.

In some embodiments, the antibody or antigen binding fragment thereofhas one or more of the following characteristics: (a) the ABspecifically binds human PDL1, murine PDL1, and cynomolgus monkey PDL1;(b) the AB inhibits binding of human B7-1 and human PD1 to human PDL1;(c) the AB inhibits binding of murine B7-1 and murine PD1 to murinePDL1; and (d) the AB inhibits binding of cynomolgus monkey B7-1 andcynomolgus monkey PD1 to cynomolgus monkey PDL1.

In some embodiments, the antibody or antigen binding fragment thereofblocks the ability of a natural ligand to bind to the mammalian PDL1with an EC₅₀ less than or equal to 0.5 nM, less than or equal to 1 nM,less than or equal to 2 nM, less than or equal to 3 nM, less than orequal to 4 nM, less than or equal to 5 nM, less than or equal to 6 nM,less than or equal to 7 nM, less than or equal to 8 nM, less than orequal to 9 nM, and/or less than or equal to 10 nM.

In some embodiments, the antibody or antigen binding fragment thereofblocks the ability of a natural ligand to bind to the mammalian PDL1with an EC₅₀ in the range of 0.5 nM to 10 nM, 0.5 nM to 5 nM, 0.5 nM to3 nM, 0.5 nM to 2 nM, 0.5 nM to 1 nM, 1 nM to 10 nM, 1 nM to 5 nM, 1 nMto 3 nM, 1 nM to 2 nM, 2 nM to 10 nM, 2 nM to 5 nM, 2 nM to 3 nM, 3 nMto 10 nM, 3 nM to 5 nM, or 5 nM to 10 nM. In some embodiments, thenatural ligand is a mammalian PD1. In some embodiments, the naturalligand is selected from the group consisting of: a human PD1, a murinePD1, and a cynomolgus monkey PD1.

In some embodiments, the natural ligand is a mammalian B7-1. In someembodiments, the natural ligand is selected from the group consistingof: a human B7-1, a murine B7-1, and a cynomolgus monkey B7-1.

In some embodiments, the antibody comprises a heavy chain amino acidsequence selected from the group consisting of SEQ ID NO: 14, 16, 18,20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54,and 56. In some embodiments, the antibody comprises a light chain aminoacid sequence comprising SEQ ID NO: 12 or SEQ ID NO: 58. In someembodiments, the antibody comprises a light chain amino acid sequencecomprising SEQ ID NO: 12. In some embodiments, the antibody comprises alight chain amino acid sequence comprising SEQ ID NO: 58.

In some embodiments, the antibody comprises a heavy chain amino acidsequence comprising an amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a light chainamino acid sequence comprising SEQ ID NO: 58.

In some embodiments, the antibody comprises a heavy chain amino acidsequence comprising an amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a light chainamino acid sequence comprising SEQ ID NO: 12.

In some embodiments, the antibody comprises a heavy chain amino acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36,38, 40, 42, 44, 46, 48, 50, 52, 54, and 56. In some embodiments, theantibody comprises a light chain amino acid that is at least 90%, 91%,92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the amino acidsequence of SEQ ID NO: 58. In some embodiments, the antibody comprises alight chain amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO:12. In some embodiments, the antibody comprises a heavy chain amino acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a light chainamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the amino acid sequence of SEQ ID NO: 58. In someembodiments, the antibody comprises a heavy chain amino acid sequencethat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to an amino acid sequence selected from the group consistingof SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a light chain amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence of SEQ ID NO: 12.

In some embodiments, the antibody comprises the heavy chain amino acidsequence of SEQ ID NO: 46 and the light chain amino acid sequence of SEQID NO: 58. In some embodiments, the antibody comprises the heavy chainamino acid sequence of SEQ ID NO: 46 and the light chain amino acidsequence of SEQ ID NO: 12.

In some embodiments, the antibody comprises a heavy chain amino acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to the amino acid of SEQ ID NO: 46. In some embodiments,the antibody comprises a light chain amino acid that is at least 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the aminoacid sequence of SEQ ID NO: 58. In some embodiments, the antibodycomprises a light chain amino acid that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% identical to the amino acid sequence ofSEQ ID NO: 12. In some embodiments, the antibody comprises a heavy chainamino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98% or 99% identical to the amino acid sequence selected of SEQ IDNO: 46, and a light chain amino acid that is at least 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the amino acid sequenceof SEQ ID NO: 58. In some embodiments, the antibody comprises a heavychain amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence selected ofSEQ ID NO: 46, and a light chain amino acid that is at least 90%, 91%,92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the amino acidsequence of SEQ ID NO: 12.

In some embodiments, the antibody comprises a combination of a variableheavy chain complementarity determining region 1 (VH CDR1, also referredto herein as CDRH1) sequence, a variable heavy chain complementaritydetermining region 2 (VH CDR2, also referred to herein as CDRH2)sequence, a variable heavy chain complementarity determining region 3(VH CDR3, also referred to herein as CDRH3) sequence, a variable lightchain complementarity determining region 1 (VL CDR1, also referred toherein as CDRL1) sequence, a variable light chain complementaritydetermining region 2 (VL CDR2, also referred to herein as CDRL2)sequence, and a variable light chain complementarity determining region3 (VL CDR3, also referred to herein as CDRL3) sequence, wherein at leastone CDR sequence is selected from the group consisting of a VH CDR1sequence shown in Table 16; a VH CDR2 sequence shown in Table 16; a VHCDR3 sequence shown in Table 16; a VL CDR1 sequence shown in Table 16; aVL CDR2 sequence shown in Table 16; and a VL CDR3 sequence shown inTable 16.

In some embodiments, the antibody comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein at least one CDRsequence is selected from the group consisting of a VH CDR1 sequencethat includes a sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, 99% or more identical to a VH CDR1 sequence shown inTable 16; a VH CD2 sequence that includes a sequence that is at least90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to aVH CDR2 sequence shown in Table 16; a VH CDR3 sequence that includes asequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,99% or more identical to a VH CDR3 sequence shown in Table 16; a VL CDR1sequence that includes a sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, 99% or more identical to a VL CDR1 sequenceshown in Table 16; a VL CDR2 sequence that includes a sequence that isat least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or moreidentical to a VL CDR2 sequence shown in Table 16; and a VL CDR3sequence that includes a sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, 99% or more identical to a VL CDR3 sequenceshown in Table 16.

In some embodiments, the antibody comprises a heavy chain that comprisea combination of a VH CDR1 sequence, a VH CDR2 sequence, and a VH CDR3sequence, wherein the combination is a combination of the three heavychain CDR sequences (VH CDR1, VH CDR2, VH CDR3) shown in a single row inTable 16.

In some embodiments, the antibody comprises a light chain that comprisea combination of a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein the combination is a combination of the three lightchain CDR sequences (VL CDR1, VL CDR2, VL CDR3) shown in a single row inTable 16.

In some embodiments, the antibody comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein the combination is acombination of the six CDR sequences (VH CDR1, VH CDR2, VH CDR3, VLCDR1, VL CDR2, and VL CDR3) shown in a single row in Table 16.

In some embodiments, the antibody comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein each CDR sequence inthe combination comprises a sequence that is at least 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to the correspondingCDR sequence in a combination of the six CDR sequences (VH CDR1, VHCDR2, VH CDR3, VL CDR1, VL CDR2, and VL CDR3) shown in a single row inTable 16.

In some embodiments, the antibody comprises a heavy chain that comprisea combination of a VH CDR1 sequence, a VH CDR2 sequence, and a VH CDR3sequence, wherein each CDR sequence in the combination comprises asequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,99% or more identical to the corresponding CDR sequence in a combinationof three heavy chain CDR sequences (VH CDR1, VH CDR2, VH CDR3) shown ina single row in Table 16.

In some embodiments, the antibody comprises a light chain that comprisea combination of a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein each CDR sequence in the combination comprises asequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,99% or more identical to the corresponding CDR sequence in a combinationof the three light chain CDR sequences (VL CDR1, VL CDR2, VL CDR3) shownin a single row in Table 16.

In some embodiments, the antibody comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein at least one CDRsequence is selected from the group consisting of a VL CDR1 sequencecomprising RASQSISSYLN (SEQ ID NO: 209); a VL CDR2 sequence comprisingAASSLQS (SEQ ID NO: 215); a VL CDR3 sequence comprising DNGYPST (SEQ IDNO: 228); a VH CDR1 sequence comprising SYAMS (SEQ ID NO: 212); a VHCDR2 sequence comprising SSIWRNGIVTVYADS (SEQ ID NO: 246); and a VH CDR3sequence comprising WSAAFDY (SEQ ID NO: 235).

In some embodiments, the antibody comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein the VH CDR2 sequencecomprises SSIWRNGIVTVYADS (SEQ ID NO: 246). In some embodiments, theantibody comprises a combination of a VH CDR1 sequence, a VH CDR2sequence, a VH CDR3 sequence, a VL CDR1 sequence, a VL CDR2 sequence,and a VL CDR3 sequence, wherein the VH CDR3 sequence comprises WSAAFDY(SEQ ID NO: 235). In some embodiments, the antibody comprises acombination of a VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein the VH CDR2 sequence comprises SSIWRNGIVTVYADS (SEQ IDNO: 246), and the VH CDR3 sequence comprises WSAAFDY (SEQ ID NO: 235).

In some embodiments, the antibody comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein the combinationcomprises a VL CDR1 sequence comprising RASQSISSYLN (SEQ ID NO: 209); aVL CDR2 sequence comprising AASSLQS (SEQ ID NO: 215); a VL CDR3 sequencecomprising DNGYPST (SEQ ID NO: 228); a VH CDR1 sequence comprising SYAMS(SEQ ID NO: 212); a VH CDR2 sequence comprising SSIWRNGIVTVYADS (SEQ IDNO: 246); and a VH CDR3 sequence comprising WSAAFDY (SEQ ID NO: 235).

In some embodiments, the antibody is encoded by a nucleic acid sequencethat comprises a nucleic acid sequence encoding a heavy chain amino acidsequence selected from the group consisting of SEQ ID NO: 14, 16, 18,20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54,and 56. In some embodiments, the antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a heavy chainamino acid sequence selected from the group consisting of SEQ ID NO: 46,48, 50, 52, 54, and 56. In some embodiments, the antibody is encoded bya nucleic acid sequence that comprises a nucleic acid sequence encodinga light chain amino acid sequence comprising SEQ ID NO: 12 or SEQ ID NO:58. In some embodiments, the antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a light chainamino acid sequence comprising SEQ ID NO: 12. In some embodiments, theantibody is encoded by a nucleic acid sequence that comprises a nucleicacid sequence encoding a light chain amino acid sequence comprising SEQID NO: 58 In some embodiments, the antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a heavy chainamino acid sequence selected from the group consisting of SEQ ID NO: 14,16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50,52, 54, and 56, and a nucleic acid sequence that comprises a nucleicacid sequence encoding a light chain amino acid sequence comprising SEQID NO: 58. In some embodiments, the antibody is encoded by a nucleicacid sequence that comprises a nucleic acid sequence encoding a heavychain amino acid sequence selected from the group consisting of SEQ IDNO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46,48, 50, 52, 54, and 56, and a nucleic acid sequence that comprises anucleic acid sequence encoding a light chain amino acid sequencecomprising SEQ ID NO: 12. In some embodiments, the antibody is encodedby a nucleic acid sequence that comprises a nucleic acid sequenceencoding a heavy chain amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a nucleic acidsequence that comprises a nucleic acid sequence encoding a light chainamino acid sequence comprising SEQ ID NO: 58. In some embodiments, theantibody is encoded by a nucleic acid sequence that comprises a nucleicacid sequence encoding a heavy chain amino acid sequence selected fromthe group consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and anucleic acid sequence that comprises a nucleic acid sequence encoding alight chain amino acid sequence comprising SEQ ID NO: 12.

In some embodiments, the antibody is encoded by a nucleic acid sequencethat comprises a nucleic acid sequence encoding a heavy chain amino acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36,38, 40, 42, 44, 46, 48, 50, 52, 54, and 56. In some embodiments, theantibody is encoded by a nucleic acid sequence that comprises a nucleicacid sequence encoding a heavy chain amino acid sequence that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to anamino acid sequence selected from the group consisting of SEQ ID NO: 46,48, 50, 52, 54, and 56. In some embodiments, the antibody is encoded bya nucleic acid sequence that comprises a nucleic acid sequence encodinga light chain amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO:58. In some embodiments, the antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a light chainamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the amino acid sequence of SEQ ID NO: 12. In someembodiments, the antibody is encoded by a nucleic acid sequence thatcomprises a nucleic acid sequence encoding a heavy chain amino acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36,38, 40, 42, 44, 46, 48, 50, 52, 54, and 56, and a nucleic acid sequencethat comprises a nucleic acid sequence encoding a light chain amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence of SEQ ID NO: 58. In someembodiments, the antibody is encoded by a nucleic acid sequence thatcomprises a nucleic acid sequence encoding a heavy chain amino acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36,38, 40, 42, 44, 46, 48, 50, 52, 54, and 56, and a nucleic acid sequencethat comprises a nucleic acid sequence encoding a light chain amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence of SEQ ID NO: 12. In someembodiments, the antibody is encoded by a nucleic acid sequence thatcomprises a nucleic acid sequence encoding a heavy chain amino acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a nucleic acidsequence that comprises a nucleic acid sequence encoding a light chainamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the amino acid sequence of SEQ ID NO: 58. In someembodiments, the antibody is encoded by a nucleic acid sequence thatcomprises a nucleic acid sequence encoding a heavy chain amino acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a nucleic acidsequence that comprises a nucleic acid sequence encoding a light chainamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the amino acid sequence of SEQ ID NO: 12.

In some embodiments, the antibody is encoded by a heavy chain nucleicacid sequence selected from the group consisting of SEQ ID NO: 13, 15,17, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53,and 55. In some embodiments, the antibody is encoded by a heavy chainnucleic acid sequence selected from the group consisting of SEQ ID NO:45, 47, 49, 51, 53, and 55. In some embodiments, the antibody is encodedby the light chain nucleic acid sequence of SEQ ID NO: 57. In someembodiments, the antibody is encoded by the light chain nucleic acidsequence of SEQ ID NO: 11. In some embodiments, the antibody is encodedby heavy chain nucleic acid sequence selected from the group consistingof SEQ ID NO: 13, 15, 17, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41,43, 45, 47, 49, 51, 53, and 55, and a light chain nucleic acid sequencecomprising SEQ ID NO: 57. In some embodiments, the antibody is encodedby heavy chain nucleic acid sequence selected from the group consistingof SEQ ID NO: 13, 15, 17, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41,43, 45, 47, 49, 51, 53, and 55, and a light chain nucleic acid sequencecomprising SEQ ID NO: 11. In some embodiments, the antibody is encodedby a nucleic acid sequence that comprises a heavy chain nucleic acidsequence selected from the group consisting of SEQ ID NO: 45, 47, 49,51, 53, and 55, and a light chain nucleic acid sequence comprising SEQID NO: 57. In some embodiments, the antibody is encoded by a nucleicacid sequence that comprises a heavy chain nucleic acid sequenceselected from the group consisting of SEQ ID NO: 45, 47, 49, 51, 53, and55, and a light chain nucleic acid sequence comprising SEQ ID NO: 11.

In some embodiments, the antibody is encoded by a nucleic acid sequencethat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to a heavy chain nucleic acid sequence selected from the groupconsisting of SEQ ID NO: 13, 15, 17, 21, 23, 25, 27, 29, 31, 33, 35, 37,39, 41, 43, 45, 47, 49, 51, 53, and 55. In some embodiments, theantibody is encoded by a nucleic acid sequence that is at least 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to a heavy chainnucleic acid sequence selected from the group consisting of SEQ ID NO:45, 47, 49, 51, 53, and 55. In some embodiments, the antibody is encodedby a nucleic acid sequence that is at least 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98% or 99% identical to the light chain nucleic acidsequence of SEQ ID NO: 57. In some embodiments, the antibody is encodedby a nucleic acid sequence that is at least 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98% or 99% identical to the light chain nucleic acidsequence of SEQ ID NO: 11. In some embodiments, the antibody is encodedby a nucleic acid sequence that is at least 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98% or 99% identical to a heavy chain nucleic acidsequence selected from the group consisting of SEQ ID NO: 13, 15, 17,21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, and55, and a nucleic acid sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% identical to the light chain nucleic acidsequence comprising SEQ ID NO: 57. In some embodiments, the antibody isencoded by a nucleic acid sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% identical to a heavy chain nucleic acidsequence selected from the group consisting of SEQ ID NO: 13, 15, 17,21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, and55, and a nucleic acid sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% identical to the light chain nucleic acidsequence comprising SEQ ID NO: 11. In some embodiments, the antibody isencoded by a nucleic acid sequence that comprises a nucleic acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to heavy chain nucleic acid sequence selected from thegroup consisting of SEQ ID NO: 45, 47, 49, 51, 53, and 55, and a nucleicacid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98% or 99% identical to light chain nucleic acid sequence comprising SEQID NO: 57. In some embodiments, the antibody is encoded by a nucleicacid sequence that comprises a nucleic acid sequence that is at least90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to heavychain nucleic acid sequence selected from the group consisting of SEQ IDNO: 45, 47, 49, 51, 53, and 55, and a nucleic acid sequence that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical tolight chain nucleic acid sequence comprising SEQ ID NO: 11.

In some embodiments, the antibody or antigen-binding fragment thereof isincorporated in a multispecific antibody or antigen-binding fragmentthereof, where at least one arm of the multispecific antibodyspecifically binds PDL1. In some embodiments, the antibody orantigen-binding fragment thereof is incorporated in a bispecificantibody or antigen-binding fragment thereof, where at least one arm ofthe bispecific antibody specifically binds PDL1.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a heavy chain amino acid sequenceselected from the group consisting of SEQ ID NO: 14, 16, 18, 20, 22, 24,26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, and 56. Insome embodiments, at least one arm of the multispecific antibody, e.g.,a bispecific antibody, comprises a light chain amino acid sequencecomprising SEQ ID NO: 12 or SEQ ID NO: 58. In some embodiments, at leastone arm of the multispecific antibody, e.g., a bispecific antibody,comprises a light chain amino acid sequence comprising SEQ ID NO: 12. Insome embodiments, at least one arm of the multispecific antibody, e.g.,a bispecific antibody, comprises a light chain amino acid sequencecomprising SEQ ID NO: 58.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, a heavy chain amino acid sequencecomprising an amino acid sequence selected from the group consisting ofSEQ ID NO: 46, 48, 50, 52, 54, and 56, and a light chain amino acidsequence comprising SEQ ID NO: 58.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a heavy chain amino acid sequencecomprising an amino acid sequence selected from the group consisting ofSEQ ID NO: 46, 48, 50, 52, 54, and 56, and a light chain amino acidsequence comprising SEQ ID NO: 12.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a heavy chain amino acid sequencethat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to an amino acid sequence selected from the group consistingof SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40,42, 44, 46, 48, 50, 52, 54, and 56. In some embodiments, at least onearm of the multispecific antibody, e.g., a bispecific antibody,comprises a light chain amino acid that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% identical to the amino acid sequence ofSEQ ID NO: 58. In some embodiments, at least one arm of themultispecific antibody, e.g., a bispecific antibody, comprises a lightchain amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO: 12.In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a heavy chain amino acid sequencethat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to an amino acid sequence selected from the group consistingof SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a light chain amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence of SEQ ID NO: 58. In someembodiments, at least one arm of the multispecific antibody, e.g., abispecific antibody, comprises a heavy chain amino acid sequence that isat least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical toan amino acid sequence selected from the group consisting of SEQ ID NO:46, 48, 50, 52, 54, and 56, and a light chain amino acid that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical tothe amino acid sequence of SEQ ID NO: 12.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises the heavy chain amino acidsequence of SEQ ID NO: 46 and the light chain amino acid sequence of SEQID NO: 58. In some embodiments, at least one arm of the multispecificantibody, e.g., a bispecific antibody, comprises the heavy chain aminoacid sequence of SEQ ID NO: 46 and the light chain amino acid sequenceof SEQ ID NO: 12.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a heavy chain amino acid sequencethat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid of SEQ ID NO: 46. In some embodiments, atleast one arm of the multispecific antibody, e.g., a bispecificantibody, comprises a light chain amino acid that is at least 90%, 91%,92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the amino acidsequence of SEQ ID NO: 58. In some embodiments, at least one arm of themultispecific antibody, e.g., a bispecific antibody, comprises a lightchain amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO: 12.In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a heavy chain amino acid sequencethat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence selected of SEQ ID NO: 46, and alight chain amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO:58. In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a heavy chain amino acid sequencethat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence selected of SEQ ID NO: 46, and alight chain amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO:12.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a combination of a variable heavychain complementarity determining region 1 (VH CDR1, also referred toherein as CDRH1) sequence, a variable heavy chain complementaritydetermining region 2 (VH CDR2, also referred to herein as CDRH2)sequence, a variable heavy chain complementarity determining region 3(VH CDR3, also referred to herein as CDRH3) sequence, a variable lightchain complementarity determining region 1 (VL CDR1, also referred toherein as CDRL1) sequence, a variable light chain complementaritydetermining region 2 (VL CDR2, also referred to herein as CDRL2)sequence, and a variable light chain complementarity determining region3 (VL CDR3, also referred to herein as CDRL3) sequence, wherein at leastone CDR sequence is selected from the group consisting of a VH CDR1sequence shown in Table 16; a VH CDR2 sequence shown in Table 16; a VHCDR3 sequence shown in Table 16; a VL CDR1 sequence shown in Table 16; aVL CDR2 sequence shown in Table 16; and a VL CDR3 sequence shown inTable 16.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein at least one CDRsequence is selected from the group consisting of a VH CDR1 sequencethat includes a sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, 99% or more identical to a VH CDR1 sequence shown inTable 16, a VH CD2 sequence that includes a sequence that is at least90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to aVH CDR2 sequence shown in Table 16; a VH CDR3 sequence that includes asequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,99% or more identical to a VH CDR3 sequence shown in Table 16; a VL CDR1sequence that includes a sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, 99% or more identical to a VL CDR1 sequenceshown in Table 16; a VL CDR2 sequence that includes a sequence that isat least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or moreidentical to a VL CDR2 sequence shown in Table 16; and a VL CDR3sequence that includes a sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, 99% or more identical to a VL CDR3 sequenceshown in Table 16.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein the combination is acombination of the six CDR sequences (VH CDR1, VH CDR2, VH CDR3, VLCDR1, VL CDR2, and VL CDR3) shown in a single row in Table 16.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a heavy chain that comprise acombination of a VH CDR1 sequence, a VH CDR2 sequence, and a VH CDR3sequence, wherein the combination is a combination of the three heavychain CDR sequences (VH CDR1, VH CDR2, VH CDR3) shown in a single row inTable 16.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein each CDR sequence inthe combination comprises a sequence that is at least 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to the correspondingCDR sequence in a combination of the six CDR sequences (VH CDR1, VHCDR2, VH CDR3, VL CDR1, VL CDR2, and VL CDR3) shown in a single row inTable 16.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a heavy chain that comprise acombination of a VH CDR1 sequence, a VH CDR2 sequence, and a VH CDR3sequence, wherein each CDR sequence in the combination comprises asequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,99% or more identical to the corresponding CDR sequence in a combinationof three heavy chain CDR sequences (VH CDR1, VH CDR2, VH CDR3) shown ina single row in Table 16.

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein at least one CDRsequence is selected from the group consisting of a VL CDR1 sequencecomprising RASQSISSYLN (SEQ ID NO: 209); a VL CDR2 sequence comprisingAASSLQS (SEQ ID NO: 215); a VL CDR3 sequence comprising DNGYPST (SEQ IDNO: 228); a VH CDR1 sequence comprising SYAMS (SEQ ID NO: 212); a VHCDR2 sequence comprising SSIWRNGIVTVYADS (SEQ ID NO: 246); and a VH CDR3sequence comprising WSAAFDY (SEQ ID NO: 235).

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein the VH CDR2 sequencecomprises SSIWRNGIVTVYADS (SEQ ID NO: 246). In some embodiments, atleast one arm of the multispecific antibody, e.g., a bispecificantibody, comprises a combination of a VH CDR1 sequence, a VH CDR2sequence, a VH CDR3 sequence, a VL CDR1 sequence, a VL CDR2 sequence,and a VL CDR3 sequence, wherein the VH CDR3 sequence comprises WSAAFDY(SEQ ID NO: 235). In some embodiments, at least one arm of themultispecific antibody, e.g., a bispecific antibody, comprises acombination of a VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein the VH CDR2 sequence comprises SSIWRNGIVTVYADS (SEQ IDNO: 246), and the VH CDR3 sequence comprises WSAAFDY (SEQ ID NO: 235).

In some embodiments, at least one arm of the multispecific antibody,e.g., a bispecific antibody, comprises a combination of a VH CDR1sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, aVL CDR2 sequence, and a VL CDR3 sequence, wherein the combinationcomprises a VL CDR1 sequence comprising RASQSISSYLN (SEQ ID NO: 209); aVL CDR2 sequence comprising AASSLQS (SEQ ID NO: 215); a VL CDR3 sequencecomprising DNGYPST (SEQ ID NO: 228); a VH CDR1 sequence comprising SYAMS(SEQ ID NO: 212); a VH CDR2 sequence comprising SSIWRNGIVTVYADS (SEQ IDNO: 246); and a VH CDR3 sequence comprising WSAAFDY (SEQ ID NO: 235).

The disclosure also provides activatable antibodies that include anantibody or antigen-binding fragment thereof that specifically bindsPDL1 coupled to a masking moiety (MM), such that coupling of the MMreduces the ability of the antibody or antigen-binding fragment thereofto bind PDL1. In some embodiments, the MM is coupled via a sequence thatincludes a substrate for a protease, for example, a protease that isactive in diseased tissue and/or a protease that is co-localized withPDL1 at a treatment site in a subject. The activatable anti-PDL1antibodies provided herein, also referred to herein as anti-PDL1activatable antibodies or PDL1 activatable antibodies, are stable incirculation, activated at intended sites of therapy and/or diagnosis butnot in normal, e.g., healthy tissue or other tissue not targeted fortreatment and/or diagnosis, and, when activated, exhibit binding to PDL1that is at least comparable to the corresponding, unmodified antibody.

In some embodiments, the activatable antibody that, in an activatedstate, specifically binds to mammalian PDL1, includes an antibody or anantigen binding fragment thereof (AB) that specifically binds tomammalian PDL1; a masking moiety (MM) that inhibits the binding of theAB to mammalian PDL1 when the activatable antibody is in an uncleavedstate; and a cleavable moiety (CM) coupled to the AB, wherein the CM isa polypeptide that functions as a substrate for a protease.

In some embodiments, the activatable antibody that, in an activatedstate, has one or more of the following characteristics: (a)specifically binds to mammalian PDL1; and (b) specifically blocks anatural ligand of PDL1 from binding to the mammalian PDL1, wherein theactivatable antibody comprises: an antibody or an antigen bindingfragment thereof (AB) that specifically binds to mammalian PDL1; amasking moiety (MM) that inhibits the binding of the AB to mammalianPDL1 when the activatable antibody is in an uncleaved state; and acleavable moiety (CM) coupled to the AB, wherein the CM is a polypeptidethat functions as a substrate for a protease.

In some embodiments, the activatable antibody in an uncleaved statespecifically binds to the mammalian PDL1 with a dissociation constantless than or equal to 1 nM, less than or equal to 2 nM, less than orequal to 3 nM, less than or equal to 4 nM, less than or equal to 5 nM,less than or equal to 10 nM, less than or equal to 15 nM, less than orequal to 20 nM, and/or less than or equal to 25 nM.

In some embodiments, the activatable antibody in an uncleaved statespecifically binds to the mammalian PDL1 with a dissociation constantgreater than or equal to 1 nM, greater than or equal to 2 nM, greaterthan or equal to 3 nM, greater than or equal to 4 nM, greater than orequal to 5 nM, greater than or equal to 10 nM, greater than or equal to15 nM, greater than or equal to 20 nM, and/or greater than or equal to25 nM.

In some embodiments, the activatable antibody in an uncleaved statespecifically binds to the mammalian PDL1 with a dissociation constant inthe range of 1 to 2 nM, 1 to 5 nM, 1 to 10 nM, 1 to 15 nM, 1 to 20 nM, 1to 25 nM, 2 nM to 5 nM, 2 nM to 10 nM, 2 nM to 15 nM, 2 to 20 nM, 2 to25 nM, 5 nM to 10 nM, 5 nM to 15 nM, 5 to 20 nM, 5 to 25 nM, 10 nM to 15nM, 10 to 20 nM, 10 to 25 nM, 15 to 20 nM, 15 to 25 nM, or 20 to 25 nM.

In some embodiments, the activatable antibody in an activated statespecifically binds to the mammalian PDL1 with a dissociation constant isless than or equal to 0.01 nM, less than or equal to 0.05 nM, less thanor equal to 0.1 nM, less than or equal to 0.2 nM, less than or equal to0.3 nM, less than or equal to 0.4 nM, less than or equal to 0.5 nM, lessthan or equal to 0.75 nM, and less than or equal to 1 nM.

In some embodiments, the activatable antibody in an activated statespecifically binds to the mammalian PDL1 with a dissociation constant inthe range of 0.01 nM to 1 nM, 0.05 nM to 1 nM, 0.1 nM to 1 nM, 0.2 nM to1 nM, 0.3 nM to 1 nM, 0.4 nM to 1 nM, 0.5 nM to 1 nM, 0.75 nM to 1 nM,0.01 nM to 0.75 nM, 0.05 nM to 0.75 nM, 0.1 nM to 0.75 nM, 0.2 nM to0.75 nM, 0.3 nM to 0.75 nM, 0.4 nM to 0.75 nM, 0.5 nM to 0.75 nM, 0.01nM to 0.5 nM, 0.05 nM to 0.5 nM, 0.1 nM to 0.5 nM, 0.2 nM to 0.5 nM, 0.3nM to 0.5 nM, 0.4 nM to 0.5 nM, 0.01 nM to 0.4 nM, 0.05 nM to 0.4 nM,0.1 nM to 0.4 nM, 0.2 nM to 0.4 nM, 0.3 nM to 0.4 nM, 0.01 nM to 0.3 nM,0.05 nM to 0.3 nM, 0.1 nM to 0.3 nM, 0.2 nM to 0.3 nM, 0.01 nM to 0.2nM, 0.05 nM to 0.2 nM, 0.1 nM to 0.2 nM, 0.01 nM to 0.1 nM, 0.05 nM to0.1 nM, or 0.01 nM to 0.05 nM.

In some embodiments, the AB specifically binds to the mammalian PDL1with a dissociation constant is less than or equal to 0.01 nM, less thanor equal to 0.05 nM, less than or equal to 0.1 nM, less than or equal to0.2 nM, less than or equal to 0.3 nM, less than or equal to 0.4 nM, lessthan or equal to 0.5 nM, less than or equal to 0.75 nM, and less than orequal to 1 nM.

In some embodiments, the AB specifically binds to the mammalian PDL1with a dissociation constant in the range of 0.01 nM to 1 nM, 0.05 nM to1 nM, 0.1 nM to 1 nM, 0.2 nM to 1 nM, 0.3 nM to 1 nM, 0.4 nM to 1 nM,0.5 nM to 1 nM, 0.75 nM to 1 nM, 0.01 nM to 0.75 nM, 0.05 nM to 0.75 nM,0.1 nM to 0.75 nM, 0.2 nM to 0.75 nM, 0.3 nM to 0.75 nM, 0.4 nM to 0.75nM, 0.5 nM to 0.75 nM, 0.01 nM to 0.5 nM, 0.05 nM to 0.5 nM, 0.1 nM to0.5 nM, 0.2 nM to 0.5 nM, 0.3 nM to 0.5 nM, 0.4 nM to 0.5 nM, 0.01 nM to0.4 nM, 0.05 nM to 0.4 nM, 0.1 nM to 0.4 nM, 0.2 nM to 0.4 nM, 0.3 nM to0.4 nM, 0.01 nM to 0.3 nM, 0.05 nM to 0.3 nM, 0.1 nM to 0.3 nM, 0.2 nMto 0.3 nM, 0.01 nM to 0.2 nM, 0.05 nM to 0.2 nM, 0.1 nM to 0.2 nM, 0.01nM to 0.1 nM, 0.05 nM to 0.1 nM, or 0.01 nM to 0.05 nM.

In some embodiments, the mammalian PDL1 is selected from the groupconsisting of a human PDL1, a murine PDL1, a rat PDL1, and a cynomolgusmonkey PDL1. In some embodiments, the AB specifically binds to humanPDL1, murine PDL1 or cynomolgus monkey PDL1 with a dissociation constantof less than 1 nM. In some embodiments, the mammalian PDL1 is a humanPDL1.

In some embodiments, the AB has one or more of the followingcharacteristics: (a) the AB specifically binds to human PDL1 and murinePDL1; (b) the AB specifically binds to human PDL1 and cynomolgus monkeyPDL1; and (c) the AB specifically binds to human PDL1, murine PDL1, andcynomolgus monkey PDL1.

In some embodiments, the AB has one or more of the followingcharacteristics: (a) the AB specifically binds human PDL1, murine PDL1,and cynomolgus monkey PDL1; (b) the AB inhibits binding of human B7-1and human PD1 to human PDL1; (c) the AB inhibits binding of murine B7-1and murine PD1 to murine PDL1; and (d) the AB inhibits binding ofcynomolgus monkey B7-1 and cynomolgus monkey PD1 to cynomolgus monkeyPDL1.

In some embodiments, the AB blocks the ability of a natural ligand tobind to the mammalian PDL1 with an EC₅₀ less than or equal to 0.5 nM,less than or equal to 1 nM, less than or equal to 2 nM, less than orequal to 3 nM, less than or equal to 4 nM, less than or equal to 5 nM,less than or equal to 6 nM, less than or equal to 7 nM, less than orequal to 8 nM, less than or equal to 9 nM, and/or less than or equal to10 nM.

In some embodiments, the AB blocks the ability of a natural ligand tobind to the mammalian PDL1 with an EC₅₀ of 0.5 nM to 10 nM, 0.5 nM to 5nM, 0.5 nM to 3 nM, 0.5 nM to 2 nM, 0.5 nM to 1 nM, 1 nM to 10 nM, 1 nMto 5 nM, 1 nM to 3 nM, 1 nM to 2 nM, 2 nM to 10 nM, 2 nM to 5 nM, 2 nMto 3 nM, 3 nM to 10 nM, 3 nM to 5 nM, or 5 nM to 10 nM.

In some embodiments, natural ligand is a mammalian PD1. In someembodiments, the natural ligand is selected from the group consistingof: a human PD1, a murine PD1, and a cynomolgus monkey PD1.

In some embodiments, the natural ligand is a mammalian B7-1. In someembodiments, the natural ligand is selected from the group consistingof: a human B7-1, a murine B7-1, and a cynomolgus monkey B7-1.

In some embodiments, the activatable antibody has one or more of thefollowing characteristics (a) the AB induces type 1 diabetes in anon-obese diabetic (NOD) mouse; and (b) the activatable antibody in anuncleaved state inhibits the induction of type 1 diabetes in a NODmouse.

In some embodiments, the activatable antibody inhibits the induction oftype 1 diabetes in the NOD mouse after administration of the activatableantibody at a single dose of 0.1 mg/kg to 3 mg/kg, 0.5 mg/kg to 3 mg/kg,1 mg/kg to 3 mg/kg, 2 mg/kg to 3 mg/kg, 0.1 mg/kg to 2 mg/kg, 0.5 mg/kgto 2 mg/kg, 1 mg/kg to 2 mg/kg, 0.1 mg/kg to 1 mg/kg, 0.5 mg/kg to 1mg/kg, or 0.1 mg/kg to 0.5 mg/kg.

In some embodiments, the activatable antibody induces type 1 diabetes ina subject after administration of the activatable antibody at a singledose of 1 mg/kg. In some embodiments, the subject is a NOD mouse.

In some embodiments, the activatable antibody induces type 1 diabetes ina subject after administration of the activatable antibody at singledose less than or equal to 3 mg/kg, less than or equal to 2 mg/kg, lessthan or equal to 1 mg/kg, less than or equal to 0.5 mg/kg, and/or lessthan or equal to 0.1 mg/kg.

In some embodiments, the activatable antibody induces type 1 diabetes ina subject after administration of the activatable antibody at singledose in the range selected from the group consisting of 0.1 mg/kg to 3mg/kg, 0.5 mg/kg to 3 mg/kg, 1 mg/kg to 3 mg/kg, 2 mg/kg to 3 mg/kg, 0.1mg/kg to 2 mg/kg, 0.5 mg/kg to 2 mg/kg, 1 mg/kg to 2 mg/kg, 0.1 mg/kg to1 mg/kg, 0.5 mg/kg to 1 mg/kg, and 0.1 mg/kg to 0.5 mg/kg. In someembodiments, the subject is a NOD mouse.

In some embodiments, the activatable antibody has one or more of thefollowing characteristics (a) the activatable antibody in an uncleavedstate does not induce type 1 diabetes in greater than 50% of apopulation of non-obese diabetic (NOD) mice, and the AB induces type 1diabetes in greater than 50% of a population of NOD mice.

In some embodiments, the activatable antibody does not induce type 1diabetes in greater than 50% of the population of NOD mice afteradministration to each mouse in the population a single dose less thanor equal to 3 mg/kg, less than or equal to 2 mg/kg, less than or equalto 1 mg/kg, less than or equal to 0.5 mg/kg, and/or less than or equalto 0.1 mg/kg.

In some embodiments, the activatable antibody does not induce type 1diabetes in greater than 50% of the population of NOD mice afteradministration to each mouse in the population a single dose of theactivatable antibody at a dosage of: 0.1 mg/kg to 3 mg/kg, 0.5 mg/kg to3 mg/kg, 1 mg/kg to 3 mg/kg, 2 mg/kg to 3 mg/kg, 0.1 mg/kg to 2 mg/kg,0.5 mg/kg to 2 mg/kg, 1 mg/kg to 2 mg/kg, 0.1 mg/kg to 1 mg/kg, 0.5mg/kg to 1 mg/kg, or 0.1 mg/kg to 0.5 mg/kg.

In some embodiments, the activatable antibody has one or more of thefollowing characteristics (a) the activatable antibody in an uncleavedstate does not induce type 1 diabetes in greater than 50% of apopulation of non-obese diabetic (NOD) mice when administered at asingle dose of 1 mg/kg, and (b) the AB induces type 1 diabetes ingreater than 50% of a population of NOD mice, when administered at asingle dose of 1 mg/kg.

In some embodiments, the AB induces type 1 diabetes in greater than 50%of the population of the NOD mice after administration to each mouse inthe population a single dose of the AB at a dosage less than or equal to3 mg/kg, less than or equal to 2 mg/kg, less than or equal to 1 mg/kg,less than or equal to 0.5 mg/kg, and/or less than or equal to 0.1 mg/kg.

In some embodiments, the AB induces type 1 diabetes in greater than 50%of the population of the NOD mice after administration to each mouse inthe population a single dose of the AB at a dosage of: 0.1 mg/kg to 3mg/kg, 0.5 mg/kg to 3 mg/kg, 1 mg/kg to 3 mg/kg, 2 mg/kg to 3 mg/kg, 0.1mg/kg to 2 mg/kg, 0.5 mg/kg to 2 mg/kg, 1 mg/kg to 2 mg/kg, 0.1 mg/kg to1 mg/kg, 0.5 mg/kg to 1 mg/kg, or 0.1 mg/kg to 0.5 mg/kg.

In some embodiments, he NOD mouse is a female NOD/ShiLtJ mousesubstrain.

In some embodiments, the activatable antibody inhibits the induction oftype 1 diabetes in a NOD mouse by at least 3-fold compared to the AB.

In some embodiments, the activatable antibody exhibits a safety marginthat is at least a three-fold safety margin relative to the AB.

In some embodiments, the activatable antibody in an uncleaved statebinds to a smaller percentage of a population of peripheral blood CD4+CD8+ T lymphocytes than does the AB.

In some embodiments, the activatable antibody does not bind to greaterthan 500, of the population of peripheral blood CD4+ CD8+ T lymphocytesafter administration of a single dose of the activatable antibody at adosage less than or equal to 5 mg/kg, less than or equal to 4 mg/kg,less than or equal to 3 mg/kg, less than or equal to 2 mg/kg, less thanor equal to 1 mg/kg, less than or equal to 0.5 mg/kg, and/or less thanor equal to 0.1 mg/kg.

In some embodiments, the activatable antibody does not bind to greaterthan 50% of the population of peripheral blood CD4+ CD8+ T lymphocytesafter administration of a single dose of the activatable antibody at adosage of: 0.1 mg/kg to 5 mg/kg, 0.5 mg/kg to 5 mg/kg, 1 mg/kg to 5mg/kg, 2 mg/kg to 5 mg/kg, 3 mg/kg to 5 mg/kg, 0.1 mg/kg to 3 mg/kg, 0.5mg/kg to 3 mg/kg, 1 mg/kg to 3 mg/kg, 2 mg/kg to 3 mg/kg, 0.1 mg/kg to 2mg/kg, 0.5 mg/kg to 2 mg/kg, 1 mg/kg to 2 mg/kg, 0.1 mg/kg to 1 mg/kg,0.5 mg/kg to 1 mg/kg, or 0.1 mg/kg to 0.5 mg/kg.

In some embodiments, the AB binds to greater than 50% of the populationof peripheral blood CD4+ CD8+ T lymphocytes after administration of asingle dose of the AB at a dosage of: 0.1 mg/kg to 5 mg/kg, 0.5 mg/kg to5 mg/kg, 1 mg/kg to 5 mg/kg, 2 mg/kg to 5 mg/kg, 3 mg/kg to 5 mg/kg, 0.1mg/kg to 3 mg/kg, 0.5 mg/kg to 3 mg/kg, 1 mg/kg to 3 mg/kg, 2 mg/kg to 3mg/kg, 0.1 mg/kg to 2 mg/kg, 0.5 mg/kg to 2 mg/kg, 1 mg/kg to 2 mg/kg,0.1 mg/kg to 1 mg/kg, 0.5 mg/kg to 1 mg/kg, or 0.1 mg/kg to 0.5 mg/kg.

In some embodiments, the peripheral blood CD4+ CD8+ T lymphocytes aremurine. In some embodiments, the murine peripheral blood CD4+ CD8+ Tlymphocytes are derived from a tumor-bearing mouse.

In some embodiments, the percentage of the population of peripheralblood CD4+ CD8+ T lymphocytes to which the AB binds is less than 60%when the activatable antibody is administered at a dose between 1 mg/kgand 5 mg/kg. In some embodiments, the percentage of the population ofperipheral blood CD4+ CD8+ T lymphocytes to which the AB binds is lessthan 50% when the activatable antibody is administered at a dose between1 mg/kg and 5 mg/kg. In some embodiments, the percentage of thepopulation of peripheral blood CD4+ CD8+ T lymphocytes to which the ABbinds is between 30 and 60% when the activatable antibody isadministered at a dose between 1 mg/kg and 5 mg/kg. In some embodiments,the percentage of the population of peripheral blood CD4+ CD8+ Tlymphocytes to which the AB binds is between 30 and 50% when theactivatable antibody is administered at a dose between 1 mg/kg and 5mg/kg.

The invention also provides methods of treating, preventing and/ordelaying the onset or progression of, or alleviating a symptomassociated with aberrant expression and/or activity of PDL1 in a subjectusing activatable antibodies that bind PDL1, particularly activatableantibodies that bind and neutralize or otherwise inhibit at least onebiological activity of PDL1 and/or PDL1-mediated signaling.

The activatable antibodies in an activated state bind PDL1 and include(i) an antibody or an antigen binding fragment thereof (AB) thatspecifically binds to PDL1; (ii) a masking moiety (MM) that, when theactivatable antibody is in an uncleaved state, inhibits the binding ofthe AB to PDL1; and (c) a cleavable moiety (CM) coupled to the AB,wherein the CM is a polypeptide that functions as a substrate for aprotease.

In some embodiments, the activatable antibody in the uncleaved state hasthe structural arrangement from N-terminus to C-terminus as follows:MM-CM-AB or AB-CM-MM.

In some embodiments, the activatable antibody comprises a linkingpeptide between the MM and the CM.

In some embodiments, the activatable antibody comprises a linkingpeptide between the CM and the AB.

In some embodiments, the activatable antibody comprises a first linkingpeptide (LP1) and a second linking peptide (LP2), and wherein theactivatable antibody in the uncleaved state has the structuralarrangement from N-terminus to C-terminus as follows: MM-LP1-CM-LP2-ABor AB-LP2-CM-LP1-MM. In some embodiments, the two linking peptides neednot be identical to each other.

In some embodiments, at least one of LP1 or LP2 comprises an amino acidsequence selected from the group consisting of (GS)_(n), (GGS)_(n),(GSGGS)_(n) (SEQ ID NO: 191) and (GGGS)_(n) (SEQ ID NO: 192), where n isan integer of at least one.

In some embodiments, at least one of LP1 or LP2 comprises an amino acidsequence selected from the group consisting of GGSG (SEQ ID NO: 193),GGSGG (SEQ ID NO: 194), GSGSG (SEQ ID NO: 195), GSGGG (SEQ ID NO: 196),GGGSG (SEQ ID NO: 197), and GSSSG (SEQ ID NO: 198).

In some embodiments, LP1 comprises the amino acid sequence GSSGGSGGSGGSG(SEQ ID NO: 199), GSSGGSGGSGG (SEQ ID NO: 200), GSSGGSGGSGGS (SEQ ID NO:201), GSSGGSGGSGGSGGGS (SEQ ID NO: 202), GSSGGSGGSG (SEQ ID NO: 203), orGSSGGSGGSGS (SEQ ID NO: 204).

In some embodiments, LP2 comprises the amino acid sequence GSS, GGS,GGGS (SEQ ID NO: 205), GSSGT (SEQ ID NO: 206) or GSSG (SEQ ID NO: 207).

In some embodiments, the AB has a dissociation constant of about 100 nMor less for binding to PDL1.

In some embodiments, the activatable antibody includes an antibody orantigen-binding fragment thereof (AB) that specifically binds PDL1. Insome embodiments, the antibody or antigen binding fragment thereof thatbinds PDL1 is a monoclonal antibody, domain antibody, single chain, Fabfragment, a F(ab′)₂ fragment, a scFv, a scAb, a dAb, a single domainheavy chain antibody, or a single domain light chain antibody. In someembodiments, such an antibody or antigen binding fragment thereof thatbinds PDL1 is a mouse, other rodent, chimeric, humanized or fully humanmonoclonal antibody.

In some embodiments, the activatable antibody comprises a heavy chainamino acid sequence selected from the group consisting of SEQ ID NO: 14,16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50,52, 54, and 56. In some embodiments, the activatable antibody comprisesa light chain amino acid sequence comprising SEQ ID NO: 12 or SEQ ID NO:58. In some embodiments, the activatable antibody comprises a lightchain amino acid sequence comprising SEQ ID NO: 12. In some embodiments,the activatable antibody comprises a light chain amino acid sequencecomprising SEQ ID NO: 58.

In some embodiments, the activatable antibody comprises a heavy chainamino acid sequence comprising an amino acid sequence selected from thegroup consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a lightchain amino acid sequence comprising SEQ ID NO: 58.

In some embodiments, the activatable antibody comprises a heavy chainamino acid sequence comprising an amino acid sequence selected from thegroup consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a lightchain amino acid sequence comprising SEQ ID NO: 12.

In some embodiments, the activatable antibody comprises a heavy chainamino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98% or 99% identical to an amino acid sequence selected from thegroup consisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32,34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, and 56. In some embodiments,the activatable antibody comprises a light chain amino acid that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical tothe amino acid sequence of SEQ ID NO: 58. In some embodiments, theactivatable antibody comprises a light chain amino acid that is at least90%, 91%, 92%, 93%, 94%, 958%, 96%, 97%, 98% or 99% identical to theamino acid sequence of SEQ ID NO: 12. In some embodiments, theactivatable antibody comprises a heavy chain amino acid sequence that isat least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical toan amino acid sequence selected from the group consisting of SEQ ID NO:46, 48, 50, 52, 54, and 56, and a light chain amino acid that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical tothe amino acid sequence of SEQ ID NO: 58. In some embodiments, theactivatable antibody comprises a heavy chain amino acid sequence that isat least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical toan amino acid sequence selected from the group consisting of SEQ ID NO:46, 48, 50, 52, 54, and 56, and a light chain amino acid that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical tothe amino acid sequence of SEQ ID NO: 12.

In some embodiments, the AB of the activatable anti-PDL1 antibodycomprises a heavy chain amino acid sequence selected from the groupconsisting of the heavy chain sequences shown in Table 15. In someembodiments, the AB of the activatable anti-PDL1 antibody comprises alight chain amino acid sequence selected from the group consisting ofthe light chain sequences shown in Table 15. In some embodiments, the ABof the activatable anti-PDL1 antibody comprises a heavy chain amino acidsequence selected from the group consisting of the heavy chain sequencesshown in Table 15 and a light chain amino acid sequence selected fromthe group consisting of the light chain sequences shown in Table 15.

In some embodiments, the AB of the activatable anti-PDL1 antibodycomprises a heavy chain amino acid sequence that is at least 90%, 91%,92%, 93%, 94%, 95%, 96.0%, 97%, 98% or 99% identical to an amino acidsequence selected from the group consisting of the heavy chain sequencesshown in Table 15. In some embodiments, the AB of the activatableanti-PDL1 antibody comprises a light chain amino acid sequence that isat least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical toan amino acid sequence selected from the group consisting of the lightchain sequences shown in Table 15. In some embodiments, the AB of theactivatable anti-PDL1 antibody comprises a heavy chain amino acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to an amino acid sequence selected from the groupconsisting of the heavy chain sequences shown in Table 15 and a lightchain amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to an amino acid sequence selected fromthe group consisting of the light chain sequences shown in Table 15.

In some embodiments, the activatable antibody comprises a combination ofa variable heavy chain complementarity determining region 1 (VH CDR1,also referred to herein as CDRH1) sequence, a variable heavy chaincomplementarity determining region 2 (VH CDR2, also referred to hereinas CDRH2) sequence, a variable heavy chain complementarity determiningregion 3 (VH CDR3, also referred to herein as CDRH3) sequence, avariable light chain complementarity determining region 1 (VL CDR1, alsoreferred to herein as CDRL1) sequence, a variable light chaincomplementarity determining region 2 (VL CDR2, also referred to hereinas CDRL2) sequence, and a variable light chain complementaritydetermining region 3 (VL CDR3, also referred to herein as CDRL3)sequence, wherein at least one CDR sequence is selected from the groupconsisting of a VH CDR1 sequence shown in Table 16, a VH CDR2 sequenceshown in Table 16; a VH CDR3 sequence shown in Table 16; a VL CDR1sequence shown in Table 16, a VL CDR2 sequence shown in Table 16; and aVL CDR3 sequence shown in Table 16.

In some embodiments, the activatable antibody comprises a combination ofa VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein at leastone CDR sequence is selected from the group consisting of a VH CDR1sequence that includes a sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, 99% or more identical to a VH CDR1 sequenceshown in Table 16; a VH CD2 sequence that includes a sequence that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identicalto a VH CDR2 sequence shown in Table 16; a VH CDR3 sequence thatincludes a sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98%, 99% or more identical to a VH CDR3 sequence shown in Table 16;a VL CDR1 sequence that includes a sequence that is at least 90%, 91%,92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to a VL CDR1sequence shown in Table 16; a VL CDR2 sequence that includes a sequencethat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% ormore identical to a VL CDR2 sequence shown in Table 16; and a VL CDR3sequence that includes a sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, 99% or more identical to a VL CDR3 sequenceshown in Table 16.

In some embodiments, the activatable antibody comprises a combination ofa VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein thecombination is a combination of the six CDR sequences (VH CDR1, VH CDR2,VH CDR3, VL CDR1, VL CDR2, and VL CDR3) shown in a single row in Table16.

In some embodiments, the activatable antibody comprises a heavy chainthat comprise a combination of a VH CDR1 sequence, a VH CDR2 sequence,and a VH CDR3 sequence, wherein the combination is a combination of thethree heavy chain CDR sequences (VH CDR1, VH CDR2, VH CDR3) shown in asingle row in Table 16.

In some embodiments, the activatable antibody comprises a combination ofa VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein each CDRsequence in the combination comprises a sequence that is at least 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to thecorresponding CDR sequence in a combination of the six CDR sequences (VHCDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2, and VL CDR3) shown in a singlerow in Table 16.

In some embodiments, the activatable antibody comprises a heavy chainthat comprise a combination of a VH CDR1 sequence, a VH CDR2 sequence,and a VH CDR3 sequence, wherein each CDR sequence in the combinationcomprises a sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98%, 99% or more identical to the corresponding CDR sequence in acombination of three heavy chain CDR sequences (VH CDR1, VH CDR2, VHCDR3) shown in a single row in Table 16.

In some embodiments, the activatable antibody comprises a combination ofa VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein at leastone CDR sequence is selected from the group consisting of a VL CDR1sequence comprising RASQSISSYLN (SEQ ID NO: 209); a VL CDR2 sequencecomprising AASSLQS (SEQ ID NO: 215); a VL CDR3 sequence comprisingDNGYPST (SEQ ID NO: 228); a VH CDR1 sequence comprising SYAMS (SEQ IDNO: 212); a VH CDR2 sequence comprising SSIWRNGIVTVYADS (SEQ ID NO:246); and a VH CDR3 sequence comprising WSAAFDY (SEQ ID NO: 235).

In some embodiments, the activatable antibody comprises a combination ofa VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein the VHCDR2 sequence comprises SSIWRNGIVTVYADS (SEQ ID NO: 246). In someembodiments, the activatable antibody comprises a combination of a VHCDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein the VHCDR3 sequence comprises WSAAFDY (SEQ ID NO: 235). In some embodiments,the activatable antibody comprises a combination of a VH CDR1 sequence,a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1 sequence, a VL CDR2sequence, and a VL CDR3 sequence, wherein the VH CDR2 sequence comprisesSSIWRNGIVTVYADS (SEQ ID NO: 246), and the VH CDR3 sequence comprisesWSAAFDY (SEQ ID NO: 235).

In some embodiments, the activatable antibody comprises a combination ofa VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein thecombination comprises a VL CDR1 sequence comprising RASQSISSYLN (SEQ IDNO: 209); a VL CDR2 sequence comprising AASSLQS (SEQ ID NO: 215); a VLCDR3 sequence comprising DNGYPST (SEQ ID NO: 228); a VH CDR1 sequencecomprising SYAMS (SEQ ID NO: 212); a VH CDR2 sequence comprisingSSIWRNGIVTVYADS (SEQ ID NO: 246); and a VH CDR3 sequence comprisingWSAAFDY (SEQ ID NO: 235).

In some embodiments, the activatable antibody comprises a combination ofa variable heavy chain complementarity determining region 1 (VH CDR1,also referred to herein as CDRH1) sequence, a variable heavy chaincomplementarity determining region 2 (VH CDR2, also referred to hereinas CDRH2) sequence, a variable heavy chain complementarity determiningregion 3 (VH CDR3, also referred to herein as CDRH3) sequence, avariable light chain complementarity determining region 1 (VL CDR1, alsoreferred to herein as CDRL1) sequence, a variable light chaincomplementarity determining region 2 (VL CDR2, also referred to hereinas CDRL2) sequence, and a variable light chain complementaritydetermining region 3 (VL CDR3, also referred to herein as CDRL3)sequence, wherein at least one CDR sequence is selected from the groupconsisting of a VH CDR1 sequence shown in Table 17; a VH CDR2 sequenceshown in Table 17; a VH CDR3 sequence shown in Table 17; a VL CDR1sequence shown in Table 17; a VL CDR2 sequence shown in Table 17; and aVL CDR3 sequence shown in Table 17.

In some embodiments, the activatable antibody comprises a combination ofa VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein at leastone CDR sequence is selected from the group consisting of a VH CDR1sequence that includes a sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, 99% or more identical to a VH CDR1 sequenceshown in Table 17; a VH CD2 sequence that includes a sequence that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identicalto a VH CDR2 sequence shown in Table 17; a VH CDR3 sequence thatincludes a sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98%, 99% or more identical to a VH CDR3 sequence shown in Table 17;a VL CDR1 sequence that includes a sequence that is at least 90%, 91%,92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to a VL CDR1sequence shown in Table 17; a VL CDR2 sequence that includes a sequencethat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% ormore identical to a VL CDR2 sequence shown in Table 17; and a VL CDR3sequence that includes a sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, 99% or more identical to a VL CDR3 sequenceshown in Table 17.

In some embodiments, the activatable antibody comprises a combination ofa VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein thecombination is a combination shown in Table 17.

In some embodiments, the activatable antibody comprises a combination ofa VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein each CDRsequence in the combination comprises a sequence that is at least 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identical to thecorresponding CDR sequence in a combination shown in Table 17.

In some embodiments, the activatable antibody comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 83, 85, 87,89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117,119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145,147, 149, 151, 153, 155, 157, 931, 933, 935, 937, 939, 941, 943, 945,947, 949, 951, 953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973,975, 977, 979, 981, 983, 985, 987, 989, 991, 993, 995, 997, 999, 1001,1003, 1005, 1144-1191, 1200, and 1201. In some embodiments, theactivatable antibody comprises an amino acid sequence selected from thegroup consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56. In someembodiments, the activatable antibody comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 83, 85, 87, 89, 91,93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121,123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149,151, 153, 155, 157, 931, 933, 935, 937, 939, 941, 943, 945, 947, 949,951, 953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973, 975, 977,979, 981, 983, 985, 987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005,1144-1191, 1200, and 1201, and an amino acid sequence selected from thegroup consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56.

In some embodiments, the activatable antibody comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 931, 933,935, 937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957, 959, 961,963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985, 987, 989,991, 993, 995, 997, 999, 1001, 1003, 1005, 1144-1191, 1200, and 1201. Insome embodiments, the activatable antibody comprises an amino acidsequence selected from the group consisting of SEQ ID NO: 46, 48, 50,52, 54, and 56. In some embodiments, the activatable antibody comprisesan amino acid sequence selected from the group consisting of SEQ ID NOs:931, 933, 935, 937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957,959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985,987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005, 1144-1191, 1200,and 1201, and an amino acid sequence selected from the group consistingof SEQ ID NO: 46, 48, 50, 52, 54, and 56.

In some embodiments, the activatable antibody comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 931, 933,935, 937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957, 959, 961,963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985, 987, 989,991, 993, 995, 997, 999, 1001, 1003, 1005, 1145, 1147, 1149, 1151, 1153,1155, 1157, 1159, 1161, 1163, 1165, 1167, 1169, 1171, 1173, 1175, 1177,1179, 1181, 1183, 1185, 1187, 1189, 1191, and 1201. In some embodiments,the activatable antibody comprises an amino acid sequence selected fromthe group consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56. In someembodiments, the activatable antibody comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 931, 933, 935, 937,939, 941, 943, 945, 947, 949, 951, 953, 955, 957, 959, 961, 963, 965,967, 969, 971, 973, 975, 977, 979, 981, 983, 985, 987, 989, 991, 993,995, 997, 999, 1001, 1003, 100, 1145, 1147, 1149, 1151, 1153, 1155,1157, 1159, 1161, 1163, 1165, 1167, 1169, 1171, 1173, 1175, 1177, 1179,1181, 1183, 1185, 1187, 1189, 1191, and 1201, and an amino acid sequenceselected from the group consisting of SEQ ID NO: 46, 48, 50, 52, 54, and56.

In some embodiments, the activatable antibody includes an amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to an amino acid sequence selected from the group consistingof SEQ ID NOs: 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107,109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135,137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 931, 933, 935,937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957, 959, 961, 963,965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985, 987, 989, 991,993, 995, 997, 999, 1001, 1003, 1005, 1144-1191, 1200, and 1201. In someembodiments, the activatable antibody includes an amino acid that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to anamino acid sequence selected from the group consisting of SEQ ID NO: 46,48, 50, 52, 54, and 56. In some embodiments, the activatable antibodyincludes an amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 83, 85, 87, 89, 91, 93, 95, 97, 99,101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127,129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155,157, 931, 933, 935, 937, 939, 941, 943, 945, 947, 949, 951, 953, 955,957, 959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983,985, 987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005, 1144-1191,1200, and 1201, and an amino acid that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% identical to an amino acid sequenceselected from the group consisting of SEQ ID NO: 46, 48, 50, 52, 54, and56.

In some embodiments, the activatable antibody includes an amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to an amino acid sequence selected from the group consistingof SEQ ID NOs: 931, 933, 935, 937, 939, 941, 943, 945, 947, 949, 951,953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979,981, 983, 985, 987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005,1144-1191, 1200, and 1201. In some embodiments, the activatable antibodyincludes an amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to an amino acid sequence selected fromthe group consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56. In someembodiments, the activatable antibody includes an amino acid that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to anamino acid sequence selected from the group consisting of SEQ ID NOs:931, 933, 935, 937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957,959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985,987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005, 1144-1191, 1200,and 1201, and an amino acid that is at least 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98% or 99% identical to an amino acid sequence selectedfrom the group consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56.

In some embodiments, the activatable antibody includes an amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to an amino acid sequence selected from the group consistingof SEQ ID NOs: 931, 933, 935, 937, 939, 941, 943, 945, 947, 949, 951,953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979,981, 983, 985, 987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005,1145, 1147, 1149, 1151, 1153, 1155, 1157, 1159, 1161, 1163, 1165, 1167,1169, 1171, 1173, 1175, 1177, 1179, 1181, 1183, 1185, 1187, 1189, 1191,1200, and 1201. In some embodiments, the activatable antibody includesan amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98% or 99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56. In someembodiments, the activatable antibody includes an amino acid that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to anamino acid sequence selected from the group consisting of SEQ ID NOs:931, 933, 935, 937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957,959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985,987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005, 1145, 1147, 1149,1151, 1153, 1155, 1157, 1159, 1161, 1163, 1165, 1167, 1169, 1171, 1173,1175, 1177, 1179, 1181, 1183, 1185, 1187, 1189, 1191, and 1201, and anamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56.

In some embodiments, the activatable antibody comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 83, 85, 87,89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117,119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145,147, 149, 151, 153, 155, 157, 931, 933, 935, 937, 939, 941, 943, 945,947, 949, 951, 953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973,975, 977, 979, 981, 983, 985, 987, 989, 991, 993, 995, 997, 999, 1001,1003, 1005, 1144-1191, 1200, and 1201, and the heavy chain amino acidsequence of SEQ ID NO: 46.

In some embodiments, the activatable antibody comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 931, 933,935, 937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957, 959, 961,963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985, 987, 989,991, 993, 995, 997, 999, 1001, 1003, 1005, 1144-1191, 1200, and 1201,and the heavy chain amino acid sequence of SEQ ID NO: 46.

In some embodiments, the activatable antibody comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 931, 933,935, 937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957, 959, 961,963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985, 987, 989,991, 993, 995, 997, 999, 1001, 1003, 1005, 1145, 1147, 1149, 1151, 1153,1155, 1157, 1159, 1161, 1163, 1165, 1167, 1169, 1171, 1173, 1175, 1177,1179, 1181, 1183, 1185, 1187, 1189, 1191, and 1201, and the heavy chainamino acid sequence of SEQ ID NO: 46.

In some embodiments, the activatable antibody includes an amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to an amino acid sequence selected from the group consistingof SEQ ID NOs: 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107,109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135,137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 931, 933, 935,937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957, 959, 961, 963,965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985, 987, 989, 991,993, 995, 997, 999, 1001, 1003, 1005, 1144-1191, 1200, and 1201, and anamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the heavy chain amino acid sequence of SEQ ID NO:46.

In some embodiments, the activatable antibody includes an amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to an amino acid sequence selected from the group consistingof SEQ ID NOs: 931, 933, 935, 937, 939, 941, 943, 945, 947, 949, 951,953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979,981, 983, 985, 987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005,1144-1191, 1200, and 1201, and an amino acid that is at least 90%, 91%,92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the heavy chainamino acid sequence of SEQ ID NO: 46.

In some embodiments, the activatable antibody includes an amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95, 96%, 97%, 98% or 99%identical to an amino acid sequence selected from the group consistingof SEQ ID NOs: 931, 933, 935, 937, 939, 941, 943, 945, 947, 949, 951,953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979,981, 983, 985, 987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005,1145, 1147, 1149, 1151, 1153, 1155, 1157, 1159, 1161, 1163, 1165, 1167,1169, 1171, 1173, 1175, 1177, 1179, 1181, 1183, 1185, 1187, 1189, 1191,and 1201, and an amino acid that is at least 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98% or 99% identical to the heavy chain amino acidsequence of SEQ ID NO: 46.

In some embodiments, the activatable antibody comprises the amino acidsequence of SEQ ID NO: 428. In some embodiments, the activatableantibody comprises an amino acid sequence selected from the groupconsisting of SEQ ID NO: 430, 432, 434, and 1202. In some embodiments,the activatable antibody comprises the amino acid sequence of SEQ ID NO:428, and an amino acid sequence selected from the group consisting ofSEQ ID NO: 430, 432, and 434.

In some embodiments, the activatable antibody comprises the amino acidsequence of SEQ ID NO: 1008. In some embodiments, the activatableantibody comprises an amino acid sequence selected from the groupconsisting of SEQ ID NO: 430, 432, 434, and 1202. In some embodiments,the activatable antibody comprises the amino acid sequence of SEQ ID NO:1008, and an amino acid sequence selected from the group consisting ofSEQ ID NO: 430, 432, 434, and 1202.

In some embodiments, the activatable antibody includes an amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence of SEQ ID NO: 428. In someembodiments, the activatable antibody includes an amino acid that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to anamino acid sequence selected from the group consisting of SEQ ID NO:430, 432, 434, and 1202. In some embodiments, the activatable antibodyincludes an amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO:428, and an amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to an amino acid sequence selected fromthe group consisting of SEQ ID NO: 430, 432, 434, and 1202.

In some embodiments, the activatable antibody includes an amino acidthat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence of SEQ ID NO: 1008. In someembodiments, the activatable antibody includes an amino acid that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to anamino acid sequence selected from the group consisting of SEQ ID NO:430, 432, 434, and 1202. In some embodiments, the activatable antibodyincludes an amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO:1008, and an amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to an amino acid sequence selected fromthe group consisting of SEQ ID NO: 430, 432, 434, and 1202.

In some embodiments, the activatable antibody comprises a masking moiety(MM) comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 59-81, 208, and 426; a cleavable moiety (CM)comprising an amino acid sequence selected from the group consisting ofSEQ ID NOs: 341, 352, 359, 364, 372, 377, 379, 383, 394, 437, 883-893,901-920, and 921; and a combination of a VH CDR1 sequence, a VH CDR2sequence, a VH CDR3 sequence, a VL CDR1 sequence, a VL CDR2 sequence,and a VL CDR3 sequence, wherein the combination comprises a VL CDR1sequence comprising RASQSISSYLN (SEQ ID NO: 209); a VL CDR2 sequencecomprising AASSLQS (SEQ ID NO: 215); a VL CDR3 sequence comprisingDNGYPST (SEQ ID NO: 228); a VH CDR1 sequence comprising SYAMS (SEQ IDNO: 212); a VH CDR2 sequence comprising SSIWRNGIVTVYADS (SEQ ID NO:246); and a VH CDR3 sequence comprising WSAAFDY (SEQ ID NO: 235).

In some embodiments, the activatable antibody comprises a masking moiety(MM) comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 60, 62, 63, 66-68, 71, 75, and 76; a cleavablemoiety (CM) comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 341, 364, 377, 394, 437, 883-893, 901-911, and920; and a combination of a VH CDR1 sequence, a VH CDR2 sequence, a VHCDR3 sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein the combination comprises a VL CDR1 sequencecomprising RASQSISSYLN (SEQ ID NO: 209); a VL CDR2 sequence comprisingAASSLQS (SEQ ID NO: 215); a VL CDR3 sequence comprising DNGYPST (SEQ IDNO: 228); a VH CDR1 sequence comprising SYAMS (SEQ ID NO: 212); a VHCDR2 sequence comprising SSIWRNGIVTVYADS (SEQ ID NO: 246), and a VH CDR3sequence comprising WSAAFDY (SEQ ID NO: 235).

In some embodiments, the activatable antibody comprises a masking moiety(MM) comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 59-81, 208, and 426; a cleavable moiety (CM)comprising an amino acid sequence selected from the group consisting ofSEQ ID NOs: 341, 352, 359, 364, 372, 377, 379, 383, 394, 437, 883-893,901-920, and 921; and of a variable light chain comprising the aminoacid sequence of SEQ ID NO: 58 and a variable heavy chain comprising theamino acid sequence of SEQ ID NO: 46.

In some embodiments, the activatable antibody comprises a masking moiety(MM) comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 60, 62, 63, 66-68, 71, 75, and 76; a cleavablemoiety (CM) comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 341, 364, 377, 394, 437, 883-893, 901-911, and920; and of a variable light chain comprising the amino acid sequence ofSEQ ID NO: 58 and a variable heavy chain comprising the amino acidsequence of SEQ ID NO: 46.

In some embodiments, the activatable antibody comprises a masking moiety(MM) comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 59-81, 208, and 426; a cleavable moiety (CM)comprising an amino acid sequence selected from the group consisting ofSEQ ID NOs: 341, 352, 359, 364, 372, 377, 379, 383, 394, 437, 883-893,901-920, and 921; and of a variable light chain comprising the aminoacid sequence of SEQ ID NO: 12 and a variable heavy chain comprising theamino acid sequence of SEQ ID NO: 46.

In some embodiments, the activatable antibody comprises a masking moiety(MM) comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 60, 62, 63, 66-68, 71, 75, and 76; a cleavablemoiety (CM) comprising an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 341, 364, 377, 394, 437, 883-893, 901-11, and920; and of a variable light chain comprising the amino acid sequence ofSEQ ID NO: 12 and a variable heavy chain comprising the amino acidsequence of SEQ ID NO: 46.

In some embodiments, the activatable antibody is encoded by a nucleicacid sequence that comprises a nucleic acid sequence encoding a heavychain amino acid sequence selected from the group consisting of SEQ IDNO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46,48, 50, 52, 54, and 56. In some embodiments, the activatable antibody isencoded by a nucleic acid sequence that comprises a nucleic acidsequence encoding a heavy chain amino acid sequence selected from thegroup consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56. In someembodiments, the activatable antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a light chainamino acid sequence comprising SEQ ID NO: 58. In some embodiments, theactivatable antibody is encoded by a nucleic acid sequence thatcomprises a nucleic acid sequence encoding a light chain amino acidsequence comprising SEQ ID NO: 12. In some embodiments, the activatableantibody is encoded by a nucleic acid sequence that comprises a nucleicacid sequence encoding a heavy chain amino acid sequence selected fromthe group consisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30,32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, and 56, and a nucleicacid sequence that comprises a nucleic acid sequence encoding a lightchain amino acid sequence comprising SEQ ID NO: 58. In some embodiments,the activatable antibody is encoded by a nucleic acid sequence thatcomprises a nucleic acid sequence encoding a heavy chain amino acidsequence selected from the group consisting of SEQ ID NO: 14, 16, 18,20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54,and 56, and a nucleic acid sequence that comprises a nucleic acidsequence encoding a light chain amino acid sequence comprising SEQ IDNO: 12. In some embodiments, the activatable antibody is encoded by anucleic acid sequence that comprises a nucleic acid sequence encoding aheavy chain amino acid sequence selected from the group consisting ofSEQ ID NO: 46, 48, 50, 52, 54, and 56, and a nucleic acid sequence thatcomprises a nucleic acid sequence encoding a light chain amino acidsequence comprising SEQ ID NO: 58. In some embodiments, the activatableantibody is encoded by a nucleic acid sequence that comprises a nucleicacid sequence encoding a heavy chain amino acid sequence selected fromthe group consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and anucleic acid sequence that comprises a nucleic acid sequence encoding alight chain amino acid sequence comprising SEQ ID NO: 12.

In some embodiments, the activatable antibody is encoded by a nucleicacid sequence that comprises a nucleic acid sequence encoding a heavychain amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to an amino acid sequence selected fromthe group consisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30,32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, and 56. In someembodiments, the activatable antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a heavy chainamino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98% or 99% identical to an amino acid sequence selected from thegroup consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56. In someembodiments, the activatable antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a light chainamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the amino acid sequence of SEQ ID NO: 58. In someembodiments, the activatable antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a light chainamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the amino acid sequence of SEQ ID NO: 12. In someembodiments, the activatable antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a heavy chainamino acid sequence that is at least 90%, 91%, 92%, 930%, 94%, 95%, 96%,97%, 98% or 99% identical to an amino acid sequence selected from thegroup consisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32,34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, and 56, and a nucleic acidsequence that comprises a nucleic acid sequence encoding a light chainamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the amino acid sequence of SEQ ID NO: 58. In someembodiments, the activatable antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a heavy chainamino acid sequence that is at least 90%, 91%, 92%, 930%, 94%, 95%, 96%,97%, 98% or 99%6 identical to an amino acid sequence selected from thegroup consisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32,34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, and 56, and a nucleic acidsequence that comprises a nucleic acid sequence encoding a light chainamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the amino acid sequence of SEQ ID NO: 12. In someembodiments, the activatable antibody is encoded by a nucleic acidsequence that comprises a nucleic acid sequence encoding a heavy chainamino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98% or 99% identical to an amino acid sequence selected from thegroup consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a nucleicacid sequence that comprises a nucleic acid sequence encoding a lightchain amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO: 58.In some embodiments, the activatable antibody is encoded by a nucleicacid sequence that comprises a nucleic acid sequence encoding a heavychain amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to an amino acid sequence selected fromthe group consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and anucleic acid sequence that comprises a nucleic acid sequence encoding alight chain amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO:12.

In some embodiments, the activatable antibody is encoded by a heavychain nucleic acid sequence selected from the group consisting of SEQ IDNO: 13, 15, 17, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47,49, 51, 53, and 55. In some embodiments, the activatable antibody isencoded by a heavy chain nucleic acid sequence selected from the groupconsisting of SEQ ID NO: 45, 47, 49, 51, 53, and 55. In someembodiments, the activatable antibody is encoded by the light chainnucleic acid sequence of SEQ ID NO: 57. In some embodiments, theactivatable antibody is encoded by the light chain nucleic acid sequenceof SEQ ID NO: 11. In some embodiments, the activatable antibody isencoded by heavy chain nucleic acid sequence selected from the groupconsisting of SEQ ID NO: 13, 15, 17, 21, 23, 25, 27, 29, 31, 33, 35, 37,39, 41, 43, 45, 47, 49, 51, 53, and 55, and a light chain nucleic acidsequence comprising SEQ ID NO: 57. In some embodiments, the activatableantibody is encoded by heavy chain nucleic acid sequence selected fromthe group consisting of SEQ ID NO. 13, 15, 17, 21, 23, 25, 27, 29, 31,33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, and 55, and a light chainnucleic acid sequence comprising SEQ ID NO: 11. In some embodiments, theactivatable antibody is encoded by a nucleic acid sequence thatcomprises a heavy chain nucleic acid sequence selected from the groupconsisting of SEQ ID NO: 45, 47, 49, 51, 53, and 55, and a light chainnucleic acid sequence comprising SEQ ID NO: 57. In some embodiments, theactivatable antibody is encoded by a nucleic acid sequence thatcomprises a heavy chain nucleic acid sequence selected from the groupconsisting of SEQ ID NO: 45, 47, 49, 51, 53, and 55, and a light chainnucleic acid sequence comprising SEQ ID NO: 11.

In some embodiments, the activatable antibody is encoded by a nucleicacid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98% or 99% identical to a heavy chain nucleic acid sequence selectedfrom the group consisting of SEQ ID NO: 13, 15, 17, 21, 23, 25, 27, 29,31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, and 55. In someembodiments, the activatable antibody is encoded by a nucleic acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to a heavy chain nucleic acid sequence selected from thegroup consisting of SEQ ID NO: 45, 47, 49, 51, 53, and 55. In someembodiments, the activatable antibody is encoded by a nucleic acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to the light chain nucleic acid sequence of SEQ ID NO: 57.In some embodiments, the activatable antibody is encoded by a nucleicacid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98% or 99% identical to the light chain nucleic acid sequence of SEQ IDNO: 11. In some embodiments, the activatable antibody is encoded by anucleic acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to a heavy chain nucleic acid sequenceselected from the group consisting of SEQ ID NO: 13, 15, 17, 21, 23, 25,27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, and 55, and anucleic acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the light chain nucleic acid sequencecomprising SEQ ID NO: 57. In some embodiments, the activatable antibodyis encoded by a nucleic acid sequence that is at least 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98% or 99% identical to a heavy chain nucleicacid sequence selected from the group consisting of SEQ ID NO: 13, 15,17, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53,and 55, and a nucleic acid sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98% or 99% identical to the light chain nucleic acidsequence comprising SEQ ID NO: 11. In some embodiments, the activatableantibody is encoded by a nucleic acid sequence that comprises a nucleicacid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98% or 99% identical to heavy chain nucleic acid sequence selected fromthe group consisting of SEQ ID NO: 45, 47, 49, 51, 53, and 55, and anucleic acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to light chain nucleic acid sequencecomprising SEQ ID NO: 57. In some embodiments, the activatable antibodyis encoded by a nucleic acid sequence that comprises a nucleic acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or99% identical to heavy chain nucleic acid sequence selected from thegroup consisting of SEQ ID NO: 45, 47, 49, 51, 53, and 55, and a nucleicacid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98% or 99% identical to light chain nucleic acid sequence comprising SEQID NO: 11.

In some embodiments, the MM has a dissociation constant for binding tothe AB that is greater than the dissociation constant of the AB to PDL1.

In some embodiments, the MM has a dissociation constant for binding tothe AB that is no more than the dissociation constant of the AB to PDL1.

In some embodiments, the MM has a dissociation constant for binding tothe AB that is less than the dissociation constant of the AB to PDL1.

In some embodiments, the MM has a dissociation constant for binding tothe AB that is approximately equal to the dissociation constant of theAB to PDL1.

In some embodiments, the MM does not interfere or compete with the ABfor binding to PDL1 when the activatable antibody is in a cleaved state.

In some embodiments, the MM is a polypeptide of about 2 to 40 aminoacids in length. In some embodiments, the MM is a polypeptide of up toabout 40 amino acids in length.

In some embodiments, the MM polypeptide sequence is different from thatof PDL1. In some embodiments, the MM polypeptide sequence is no morethan 50% identical to any natural binding partner of the AB. In someembodiments, the MM polypeptide sequence is different from that of PDL1and is no more than 40%, 30%, 25%, 20%, 15%, or 10% identical to anynatural binding partner of the AB.

In some embodiments, the MM comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 59-81, 208, and 426. In someembodiments, the MM comprises an amino acid sequence that is at least90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to an aminoacid sequence selected from the group consisting of SEQ ID NOs: 59-81,208, and 426.

In some embodiments, the coupling of the MM to the AB reduces theability of the AB to bind PDL1 such that the dissociation constant(K_(d)) of the AB when coupled to the MM towards PDL1 is at least twotimes greater than the K_(d) of the AB when not coupled to the MMtowards PDL1.

In some embodiments, the coupling of the MM to the AB reduces theability of the AB to bind PDL1 such that the dissociation constant(K_(d)) of the AB when coupled to the MM towards PDL1 is at least fivetimes greater than the K_(d) of the AB when not coupled to the MMtowards PDL1.

In some embodiments, the coupling of the MM to the AB reduces theability of the AB to bind PDL1 such that the dissociation constant(K_(d)) of the AB when coupled to the MM towards PDL1 is at least 10times greater than the K_(d) of the AB when not coupled to the MMtowards PDL1.

In some embodiments, the coupling of the MM to the AB reduces theability of the AB to bind PDL1 such that the dissociation constant(K_(d)) of the AB when coupled to the MM towards PDL1 is at least 20times greater than the K_(d) of the AB when not coupled to the MMtowards PDL1.

In some embodiments, the coupling of the MM to the AB reduces theability of the AB to bind PDL1 such that the dissociation constant(K_(d)) of the AB when coupled to the MM towards PDL1 is at least 40times greater than the K_(d) of the AB when not coupled to the MMtowards PDL1.

In some embodiments, the coupling of the MM to the AB reduces theability of the AB to bind PDL1 such that the dissociation constant(K_(d)) of the AB when coupled to the MM towards PDL1 is at least 100times greater than the K_(d) of the AB when not coupled to the MMtowards PDL1.

In some embodiments, the coupling of the MM to the AB reduces theability of the AB to bind PDL1 such that the dissociation constant(K_(d)) of the AB when coupled to the MM towards PDL1 is at least 1000times greater than the K_(d) of the AB when not coupled to the MMtowards PDL1.

In some embodiments, the coupling of the MM to the AB reduces theability of the AB to bind PDL1 such that the dissociation constant(K_(d)) of the AB when coupled to the MM towards PDL1 is at least 10,000times greater than the K_(d) of the AB when not coupled to the MMtowards PDL1.

In some embodiments, in the presence of PDL1, the MM reduces the abilityof the AB to bind PDL1 by at least 90% when the CM is uncleaved, ascompared to when the CM is cleaved when assayed in vitro using a targetdisplacement assay such as, for example, the assay described in PCTPublication No. WO 2010/081173, the contents of which are herebyincorporated by reference in their entirety.

In some embodiments, the protease that cleaves the CM is active, e.g.,up-regulated, in diseased tissue, and the protease cleaves the CM in theactivatable antibody when the activatable antibody is exposed to theprotease.

In some embodiments, the protease is co-localized with PDL1 in a tissue,and the protease cleaves the CM in the activatable antibody when theactivatable antibody is exposed to the protease.

In some embodiments, the protease is present at relatively higher levelsin or in close proximity to target-containing tissue of a treatment siteor diagnostic site than in tissue of non-treatment sites (for example inhealthy tissue), and the protease cleaves the CM in the activatableantibody when the activatable antibody is exposed to the protease.

In some embodiments, the CM is positioned in the activatable antibodysuch that when the activatable antibody is in the uncleaved state,binding of the activatable antibody to PDL1 is reduced to occur with adissociation constant that is at least twofold greater than thedissociation constant of an unmodified AB binding to PDL1, whereas inthe cleaved state (i.e., when the activatable antibody is in the cleavedstate), the AB binds PDL1.

In some embodiments, the CM is positioned in the activatable antibodysuch that when the activatable antibody is in the uncleaved state,binding of the activatable antibody to PDL1 is reduced to occur with adissociation constant that is at least fivefold greater than thedissociation constant of an unmodified AB binding to PDL1, whereas inthe cleaved state (i.e., when the activatable antibody is in the cleavedstate), the AB binds PDL1.

In some embodiments, the CM is positioned in the activatable antibodysuch that when the activatable antibody is in the uncleaved state,binding of the activatable antibody to PDL1 is reduced to occur with adissociation constant that is at least 10-fold greater than thedissociation constant of an unmodified AB binding to PDL1, whereas inthe cleaved state (i.e., when the activatable antibody is in the cleavedstate), the AB binds PDL1.

In some embodiments, the CM is positioned in the activatable antibodysuch that when the activatable antibody is in the uncleaved state,binding of the activatable antibody to PDL1 is reduced to occur with adissociation constant that is at least 20-fold greater than thedissociation constant of an unmodified AB binding to PDL1, whereas inthe cleaved state (i.e., when the activatable antibody is in the cleavedstate), the AB binds PDL1.

In some embodiments, the CM is positioned in the activatable antibodysuch that when the activatable antibody is in the uncleaved state,binding of the activatable antibody to PDL1 is reduced to occur with adissociation constant that is at least 40-fold greater than thedissociation constant of an unmodified AB binding to PDL1, whereas inthe cleaved state, the AB binds PDL1.

In some embodiments, the CM is positioned in the activatable antibodysuch that when the activatable antibody is in the uncleaved state,binding of the activatable antibody to PDL1 is reduced to occur with adissociation constant that is at least 50-fold greater than thedissociation constant of an unmodified AB binding to PDL1, whereas inthe cleaved state, the AB binds PDL1.

In some embodiments, the CM is positioned in the activatable antibodysuch that when the activatable antibody is in the uncleaved state,binding of the activatable antibody to PDL1 is reduced to occur with adissociation constant that is at least 100-fold greater than thedissociation constant of an unmodified AB binding to PDL1, whereas inthe cleaved state, the AB binds PDL1.

In some embodiments, the CM is positioned in the activatable antibodysuch that when the activatable antibody is in the uncleaved state,binding of the activatable antibody to PDL1 is reduced to occur with adissociation constant that is at least 200-fold greater than thedissociation constant of an unmodified AB binding to PDL1, whereas inthe cleaved state, the AB binds PDL1.

In some embodiments, the CM is a polypeptide of up to 15 amino acids inlength.

In some embodiments, the CM is a polypeptide that includes a firstcleavable moiety (CM1) that is a substrate for at least one matrixmetalloprotease (MMP) and a second cleavable moiety (CM2) that is asubstrate for at least one serine protease (SP). In some embodiments,each of the CM1 substrate sequence and the CM2 substrate sequence of theCM1-CM2 substrate is independently a polypeptide of up to 15 amino acidsin length.

In some embodiments, the CM is a substrate for at least one proteasethat is or is believed to be up-regulated in cancer. In someembodiments, the CM is a substrate for at least one protease that is oris believed to be up-regulated in inflammation. In some embodiments, theCM is a substrate for at least one protease that is or is believed to beup-regulated in autoimmunity.

In some embodiments, the CM is a substrate for at least one proteaseselected from the group consisting of a matrix metalloprotease (MMP), athrombin, a neutrophil elastase, a cysteine protease, a legumain, and aserine protease, such as a matriptase (MT-SP1), and a urokinase (uPA).Without being bound by theory, it is believed that these proteases areup-regulated in at least one of cancer, inflammation, and/orautoimmunity.

Exemplary substrates include but are not limited to substrates cleavableby one or more of the following enzymes or proteases listed in Table 12.

In some embodiments, the CM is selected for use with a specificprotease, for example a protease that is known to be co-localized withthe target of the activatable antibody.

In some embodiments, the CM is selected for use with a specificprotease, for example a protease that is known to be in close proximityto the target of the activatable antibody.

In some embodiments, the CM is a substrate for at least one MMP.Examples of MMPs include the MMPs listed in the Table 12. In someembodiments, the CM is a substrate for a protease selected from thegroup consisting of MMP 9, MMP14, MMP1, MMP3, MMP13, MMP17, MMP11, andMMP19. In some embodiments the CM is a substrate for MMP9. In someembodiments, the CM is a substrate for MMP14.

In some embodiments, the CM is a substrate that includes the sequenceTGRGPSWV (SEQ ID NO: 338); SARGPSRW (SEQ ID NO: 339); TARGPSFK (SEQ IDNO: 340); LSGRSDNH (SEQ ID NO: 341); GGWHTGRN (SEQ ID NO: 342); HTGRSGAL(SEQ ID NO: 343); PLTGRSGG (SEQ ID NO: 344); AARGPAIH (SEQ ID NO: 345);RGPAFNPM (SEQ ID NO: 346); SSRGPAYL (SEQ ID NO: 347); RGPATPIM (SEQ IDNO: 348); RGPA (SEQ ID NO: 349); GGQPSGMWGW (SEQ ID NO: 350); FPRPLGITGL(SEQ ID NO: 351); VHMPLGFLGP (SEQ ID NO: 352); SPLTGRSG (SEQ ID NO:353); SAGFSLPA (SEQ ID NO: 354); LAPLGLQRR (SEQ ID NO: 355); SGGPLGVR(SEQ ID NO: 356); PLGL (SEQ ID NO: 357); LSGRSGNH (SEQ ID NO: 883);SGRSANPRG (SEQ ID NO: 884); LSGRSDDH (SEQ ID NO: 885); LSGRSDIH (SEQ IDNO: 886); LSGRSDQH (SEQ ID NO: 887); LSGRSDTH (SEQ ID NO: 888); LSGRSDYH(SEQ ID NO: 889); LSGRSDNP (SEQ ID NO: 890); LSGRSANP (SEQ ID NO: 891);LSGRSANI (SEQ ID NO: 892); and/or LSGRSDNI (SEQ ID NO: 893).

In some embodiments, the CM comprises the amino acid sequence LSGRSDNH(SEQ ID NO: 341). In some embodiments, the CM comprises the amino acidsequence TGRGPSWV (SEQ ID NO: 338). In some embodiments, the CMcomprises the amino acid sequence PLTGRSGG (SEQ ID NO: 344). In someembodiments, the CM comprises the amino acid sequence GGQPSGMWGW (SEQ IDNO: 350). In some embodiments, the CM comprises the amino acid sequenceFPRPLGITGL (SEQ ID NO: 351). In some embodiments, the CM comprises theamino acid sequence VHMPLGFLGP (SEQ ID NO: 352). In some embodiments,the CM comprises the amino acid sequence PLGL (SEQ ID NO: 357). In someembodiments, the CM comprises the amino acid sequence SARGPSRW (SEQ IDNO: 339). In some embodiments, the CM comprises the amino acid sequenceTARGPSFK (SEQ ID NO: 340). In some embodiments, the CM comprises theamino acid sequence GGWHTGRN (SEQ ID NO: 342). In some embodiments, theCM comprises the amino acid sequence HTGRSGAL (SEQ ID NO: 343). In someembodiments, the CM comprises the amino acid sequence AARGPAIH (SEQ IDNO: 345). In some embodiments, the CM comprises the amino acid sequenceRGPAFNPM (SEQ ID NO: 346). In some embodiments, the CM comprises theamino acid sequence SSRGPAYL (SEQ ID NO: 347). In some embodiments, theCM comprises the amino acid sequence RGPATPIM (SEQ ID NO: 348). In someembodiments, the CM comprises the amino acid sequence RGPA (SEQ ID NO:349). In some embodiments, the CM comprises the amino acid sequenceLSGRSGNH (SEQ ID NO: 883). In some embodiments, the CM comprises theamino acid sequence SGRSANPRG (SEQ ID NO: 884). In some embodiments, theCM comprises the amino acid sequence LSGRSDDH (SEQ ID NO: 885). In someembodiments, the CM comprises the amino acid sequence LSGRSDIH (SEQ IDNO: 886). In some embodiments, the CM comprises the amino acid sequenceLSGRSDQH (SEQ ID NO: 887). In some embodiments, the CM comprises theamino acid sequence LSGRSDTH (SEQ ID NO: 888). In some embodiments, theCM comprises the amino acid sequence LSGRSDYH (SEQ ID NO: 889). In someembodiments, the CM comprises the amino acid sequence LSGRSDNP (SEQ IDNO: 890). In some embodiments, the CM comprises the amino acid sequenceLSGRSANP (SEQ ID NO: 891). In some embodiments, the CM comprises theamino acid sequence LSGRSANI (SEQ ID NO: 892). In some embodiments, theCM comprises the amino acid sequence LSGRSDNI (SEQ ID NO: 893)

In some embodiments, the CM is a substrate for an MMP and includes thesequence ISSGLSS (SEQ ID NO: 358); QNQALRMA (SEQ ID NO: 359); AQNLLGMV(SEQ ID NO: 360); STFPFGMF (SEQ ID NO: 361); PVGYTSSL (SEQ ID NO: 362),DWLYWPGI (SEQ ID NO: 363), ISSGLLSS (SEQ ID NO: 364), LKAAPRWA (SEQ IDNO: 365); GPSHLVLT (SEQ ID NO: 366), LPGGLSPW (SEQ ID NO: 367); MGLFSEAG(SEQ ID NO: 368); SPLPLRVP (SEQ ID NO: 369); RMHLRSLG (SEQ ID NO: 370);LAAPLGLL (SEQ ID NO: 371); AVGLLAPP (SEQ ID NO: 372); LLAPSHRA (SEQ IDNO: 373). PAGLWLDP (SEQ ID NO: 374); MIAPVAYR (SEQ ID NO: 894); RPSPMWAY(SEQ ID NO: 895); WATPRPMR (SEQ ID NO: 896); FRLLDWQW (SEQ ID NO: 897);ISSGL (SEQ ID NO: 898); ISSGLLS (SEQ ID NO: 899); and/or ISSGLL (SEQ IDNO: 900).

In some embodiments, the CM comprises the amino acid sequence ISSGLSS(SEQ ID NO: 358). In some embodiments, the CM comprises the amino acidsequence QNQALRMA (SEQ ID NO: 359). In some embodiments, the CMcomprises the amino acid sequence AQNLLGMV (SEQ ID NO: 360). In someembodiments, the CM comprises the amino acid sequence STFPFGMF (SEQ IDNO: 361). In some embodiments, the CM comprises the amino acid sequencePVGYTSSL (SEQ ID NO: 362). In some embodiments, the CM comprises theamino acid sequence DWLYWPGI (SEQ ID NO: 363). In some embodiments, theCM comprises the amino acid sequence ISSGLLSS (SEQ ID NO: 364). In someembodiments, the CM comprises the amino acid sequence LKAAPRWA (SEQ IDNO: 365). In some embodiments, the CM comprises the amino acid sequenceGPSHLVLT (SEQ ID NO: 366). In some embodiments, the CM comprises theamino acid sequence LPGGLSPW (SEQ ID NO: 367). In some embodiments, theCM comprises the amino acid sequence MGLFSEAG (SEQ ID NO: 368). In someembodiments, the CM comprises the amino acid sequence SPLPLRVP (SEQ IDNO: 369). In some embodiments, the CM comprises the amino acid sequenceRMHLRSLG (SEQ ID NO: 370). In some embodiments, the CM comprises theamino acid sequence LAAPLGLL (SEQ ID NO: 371). In some embodiments, theCM comprises the amino acid sequence AVGLLAPP (SEQ ID NO: 372). In someembodiments, the CM comprises the amino acid sequence LLAPSHRA (SEQ IDNO: 373). In some embodiments, the CM comprises the amino acid sequencePAGLWLDP (SEQ ID NO: 374). In some embodiments, the CM comprises theamino acid sequence MIAPVAYR (SEQ ID NO: 894). In some embodiments, theCM comprises the amino acid sequence RPSPMWAY (SEQ ID NO: 895). In someembodiments, the CM comprises the amino acid sequence WATPRPMR (SEQ IDNO: 896). In some embodiments, the CM comprises the amino acid sequenceFRLLDWQW (SEQ ID NO: 897). In some embodiments, the CM comprises theamino acid sequence ISSGL (SEQ ID NO: 898). In some embodiments, the CMcomprises the amino acid sequence ISSGLLS (SEQ ID NO: 899). In someembodiments, the CM comprises the amino acid sequence ISSGLL (SEQ ID NO:900).

In some embodiments, the CM is a substrate for thrombin. In someembodiments, the CM is a substrate for thrombin and includes thesequence GPRSFGL (SEQ ID NO. 375) or GPRSFG (SEQ ID NO: 376). In someembodiments, the CM comprises the amino acid sequence GPRSFGL (SEQ IDNO: 375). In some embodiments, the CM comprises the amino acid sequenceGPRSFG (SEQ ID NO: 376).

In some embodiments, the CM comprises an amino acid sequence selectedfrom the group consisting of NTLSGRSENHSG (SEQ ID NO: 435); NTLSGRSGNHGS(SEQ ID NO: 436); TSTSGRSANPRG (SEQ ID NO: 437); TSGRSANP (SEQ ID NO:438); VAGRSMRP (SEQ ID NO: 439); VVPEGRRS (SEQ ID NO: 440); ILPRSPAF(SEQ ID NO: 441); MVLGRSLL (SEQ ID NO: 442); QGRAITFI (SEQ ID NO: 443);SPRSIMLA (SEQ ID NO: 444); and SMLRSMPL (SEQ ID NO: 445).

In some embodiments, the CM comprises the amino acid sequenceNTLSGRSENHSG (SEQ ID NO: 435). In some embodiments, the CM comprises theamino acid sequence NTLSGRSGNHGS (SEQ ID NO: 436). In some embodiments,the CM comprises the amino acid sequence TSTSGRSANPRG (SEQ ID NO: 437).In some embodiments, the CM comprises the amino acid sequence TSGRSANP(SEQ ID NO: 438). In some embodiments, the CM comprises the amino acidsequence VAGRSMRP (SEQ ID NO: 439). In some embodiments, the CMcomprises the amino acid sequence VVPEGRRS (SEQ ID NO: 440). In someembodiments, the CM comprises the amino acid sequence ILPRSPAF (SEQ IDNO: 441).

In some embodiments, the CM comprises the amino acid sequence MVLGRSLL(SEQ ID NO: 442). In some embodiments, the CM comprises the amino acidsequence QGRAITFI (SEQ ID NO: 443). In some embodiments, the CMcomprises the amino acid sequence SPRSIMLA (SEQ ID NO: 444). In someembodiments, the CM comprises the amino acid sequence SMLRSMPL (SEQ IDNO: 445).

In some embodiments, the CM is a substrate for a neutrophil elastase. Insome embodiments, the CM is a substrate for a serine protease. In someembodiments, the CM is a substrate for uPA. In some embodiments, the CMis a substrate for legumain. In some embodiments, the CM is a substratefor matriptase. In some embodiments, the CM is a substrate for acysteine protease. In some embodiments, the CM is a substrate for acysteine protease, such as a cathepsin.

In some embodiments, the CM is a CM1-CM2 substrate and includes thesequence ISSGLLSGRSDNH (SEQ ID NO: 377); ISSGLLSSGGSGGSLSGRSDNH (SEQ IDNO: 378); AVGLLAPPGGTSTSGRSANPRG (SEQ ID NO: 379);TSTSGRSANPRGGGAVGLLAPP (SEQ ID NO: 380); VHMPLGFLGPGGTSTSGRSANPRG (SEQID NO: 381); TSTSGRSANPRGGGVHMPLGFLGP (SEQ ID NO: 382);AVGLLAPPGGLSGRSDNH (SEQ ID NO: 383); LSGRSDNHGGAVGLLAPP (SEQ ID NO:384); VHMPLGFLGPGGLSGRSDNH (SEQ ID NO: 385); LSGRSDNHGGVHMPLGFLGP (SEQID NO: 386); LSGRSDNHGGSGGSISSGLLSS (SEQ ID NO: 387);LSGRSGNHGGSGGSISSGLLSS (SEQ ID NO: 388); ISSGLLSSGGSGGSLSGRSGNH (SEQ IDNO: 389); LSGRSDNHGGSGGSQNQALRMA (SEQ ID NO: 390);QNQALRMAGGSGGSLSGRSDNH (SEQ ID NO: 391); LSGRSGNHGGSGGSQNQALRMA (SEQ IDNO: 392); QNQALRMAGGSGGSLSGRSGNH (SEQ ID NO: 393); ISSGLLSGRSGNH (SEQ IDNO: 394); ISSGLLSGRSANPRG (SEQ ID NO: 901); AVGLLAPPTSGRSANPRG (SEQ IDNO: 902); AVGLLAPPSGRSANPRG (SEQ ID NO: 903); ISSGLLSGRSDDH (SEQ ID NO:904); ISSGLLSGRSDIH (SEQ ID NO: 905); ISSGLLSGRSDQH (SEQ ID NO: 906);ISSGLLSGRSDTH (SEQ ID NO: 907); ISSGLLSGRSDYH (SEQ ID NO: 908);ISSGLLSGRSDNP (SEQ ID NO: 909); ISSGLLSGRSANP (SEQ ID NO: 910);ISSGLLSGRSANI (SEQ ID NO: 911); AVGLLAPPGGLSGRSDDH (SEQ ID NO: 912);AVGLLAPPGGLSGRSDIH (SEQ ID NO: 913); AVGLLAPPGGLSGRSDQH (SEQ ID NO:914); AVGLLAPPGGLSGRSDTH (SEQ ID NO: 915); AVGLLAPPGGLSGRSDYH (SEQ IDNO: 916); AVGLLAPPGGLSGRSDNP (SEQ ID NO: 917); AVGLLAPPGGLSGRSANP (SEQID NO: 918); AVGLLAPPGGLSGRSANI (SEQ ID NO: 919); ISSGLLSGRSDNI (SEQ IDNO: 920); AVGLLAPPGGLSGRSDNI (SEQ ID NO: 921); GLSGRSDNHGGAVGLLAPP (SEQID NO: 1009); and/or GLSGRSDNHGGVHMPLGFLGP (SEQ ID NO: 1010).

In some embodiments, the CM1-CM2 substrate includes the sequenceISSGLLSGRSDNH (SEQ ID NO: 377), which is also referred to herein assubstrate 2001. In some embodiments, the CM1-CM2 substrate includes thesequence ISSGLLSSGGSGGSLSGRSDNH (SEQ ID NO: 378), which is also referredto herein as substrate 1001/LP′/0001, where LP′ as used in this CM1-CM2substrate is the amino acid sequence GGSGGS (SEQ ID NO: 922). In someembodiments, the CM1-CM2 substrate includes the sequenceAVGLLAPPGGTSTSGRSANPRG (SEQ ID NO: 379), which is also referred toherein as substrate 2015 and/or substrate 1004/LP′/0003, where LP′ asused in this CM1-CM2 substrate is the amino acid sequence GG. In someembodiments, the CM1-CM2 substrate includes the sequenceTSTSGRSANPRGGGAVGLLAPP (SEQ ID NO: 380), which is also referred toherein as substrate 0003/LP′/1004, where LP′ as used in this CM1-CM2substrate is the amino acid sequence GG. In some embodiments, theCM1-CM2 substrate includes the sequence VHMPLGFLGPGGTSTSGRSANPRG (SEQ IDNO: 381), which is also referred to herein as substrate 1003/LP′/0003,where LP′ as used in this CM1-CM2 substrate is the amino acid sequenceGG. In some embodiments, the CM1-CM2 substrate includes the sequenceTSTSGRSANPRGGGVHMPLGFLGP (SEQ ID NO: 382), which is also referred toherein as substrate 0003/LP′/1003, where LP′ as used in this CM1-CM2substrate is the amino acid sequence GG. In some embodiments, theCM1-CM2 substrate includes the sequence AVGLLAPPGGLSGRSDNH (SEQ ID NO:383), which is also referred to herein as substrate 3001 and/orsubstrate 1004/LP′/0001, where LP′ as used in this CM1-CM2 substrate isthe amino acid sequence GG. In some embodiments, the CM1-CM2 substrateincludes the sequence LSGRSDNHGGAVGLLAPP (SEQ ID NO: 384), which is alsoreferred to herein as substrate 0001/LP′/1004, where LP′ as used in thisCM1-CM2 substrate is the amino acid sequence GG. In some embodiments,the CM1-CM2 substrate includes the sequence VHMPLGFLGPGGLSGRSDNH (SEQ IDNO: 385), which is also referred to herein as substrate 1003/LP′/0001,wherein LP′ as used in this CM1-CM2 substrate is the amino acid sequenceGG. In some embodiments, the CM1-CM2 substrate includes the sequenceLSGRSDNHGGVHMPLGFLGP (SEQ ID NO: 386), which is also referred to hereinas substrate 0001/LP′/1003, where LP′ as used in this CM1-CM2 substrateis the amino acid sequence GG. In some embodiments, the CM1-CM2substrate includes the sequence LSGRSDNHGGSGGSISSGLLSS (SEQ ID NO: 387),which is also referred to herein as substrate 0001/LP′/1001, where LP′as used in this CM1-CM2 substrate is the amino acid sequence GGSGGS (SEQID NO: 922). In some embodiments, the CM-CM2 substrate includes thesequence LSGRSGNHGGSGGSISSGLLSS (SEQ ID NO: 388), which is also referredto herein as substrate 0002/LP′/1001, where LP′ as used in this CM1-CM2substrate is the amino acid sequence GGSGGS (SEQ ID NO: 922). In someembodiments, the CM-CM2 substrate includes the sequenceISSGLLSSGGSGGSLSGRSGNH (SEQ ID NO: 389), which is also referred toherein as substrate 1001/LP′/0002, where LP′ as used in this CM1-CM2substrate is the amino acid sequence GGSGGS (SEQ ID NO: 922). In someembodiments, the CM1-CM2 substrate includes the sequenceLSGRSDNHGGSGGSQNQALRMA (SEQ ID NO: 390), which is also referred toherein as substrate 0001/LP′/1002, where LP′ as used in this CM1-CM2substrate is the amino acid sequence GGSGGS (SEQ ID NO: 922). In someembodiments, the CM1-CM2 substrate includes the sequenceQNQALRMAGGSGGSLSGRSDNH (SEQ ID NO: 391), which is also referred toherein as substrate 1002/LP′/0001, where LP′ as used in this CM1-CM2substrate is the amino acid sequence GGSGGS (SEQ ID NO: 922). In someembodiments, the CM1-CM2 substrate includes the sequenceLSGRSGNHGGSGGSQNQALRMA (SEQ ID NO: 392), which is also referred toherein as substrate 0002/LP′/1002, where LP′ as used in this CM1-CM2substrate is the amino acid sequence GGSGGS (SEQ ID NO: 922). In someembodiments, the CM-CM2 substrate includes the sequenceQNQALRMAGGSGGSLSGRSGNH (SEQ ID NO: 393), which is also referred toherein as substrate 1002/LP′/0002, where LP′ as used in this CM1-CM2substrate is the amino acid sequence GGSGGS (SEQ ID NO: 922). In someembodiments, the CM-CM2 substrate includes the sequence ISSGLLSGRSGNH(SEQ ID NO: 394), which is also referred to herein as substrate 2002. Insome embodiments, the CM1-CM2 substrate includes the sequenceISSGLLSGRSANPRG (SEQ ID NO: 901), which is also referred to herein assubstrate 2003. In some embodiments, the CM1-CM2 substrate includes thesequence AVGLLAPPTSGRSANPRG (SEQ ID NO: 902), which is also referred toherein as substrate 2004. In some embodiments, the CM1-CM2 substrateincludes the sequence AVGLLAPPSGRSANPRG (SEQ ID NO: 903), which is alsoreferred to herein as substrate 2005. In some embodiments, the CM1-CM2substrate includes the sequence ISSGLLSGRSDDH (SEQ ID NO: 904), which isalso referred to herein as substrate 2006. In some embodiments, theCM1-CM2 substrate includes the sequence ISSGLLSGRSDIH (SEQ ID NO: 905),which is also referred to herein as substrate 2007. In some embodiments,the CM1-CM2 substrate includes the sequence ISSGLLSGRSDQH (SEQ ID NO:906), which is also referred to herein as substrate 2008. In someembodiments, the CM1-CM2 substrate includes the sequence ISSGLLSGRSDTH(SEQ ID NO: 907), which is also referred to herein as substrate 2009. Insome embodiments, the CM1-CM2 substrate includes the sequenceISSGLLSGRSDYH (SEQ ID NO: 908), which is also referred to herein assubstrate 2010. In some embodiments, the CM1-CM2 substrate includes thesequence ISSGLLSGRSDNP (SEQ ID NO: 909), which is also referred toherein as substrate 2011. In some embodiments, the CM1-CM2 substrateincludes the sequence ISSGLLSGRSANP (SEQ ID NO: 910), which is alsoreferred to herein as substrate 2012. In some embodiments, the CM1-CM2substrate includes the sequence ISSGLLSGRSANI (SEQ ID NO: 911), which isalso referred to herein as substrate 2013. In some embodiments, theCM1-CM2 substrate includes the sequence AVGLLAPPGGLSGRSDDH (SEQ ID NO:912), which is also referred to herein as substrate 3006. In someembodiments, the CM1-CM2 substrate includes the sequenceAVGLLAPPGGLSGRSDIH (SEQ ID NO: 913), which is also referred to herein assubstrate 3007. In some embodiments, the CM1-CM2 substrate includes thesequence AVGLLAPPGGLSGRSDQH (SEQ ID NO: 914), which is also referred toherein as substrate 3008. In some embodiments, the CM1-CM2 substrateincludes the sequence AVGLLAPPGGLSGRSDTH (SEQ ID NO: 915), which is alsoreferred to herein as substrate 3009. In some embodiments, the CM1-CM2substrate includes the sequence AVGLLAPPGGLSGRSDYH (SEQ ID NO: 916),which is also referred to herein as substrate 3010. In some embodiments,the CM1-CM2 substrate includes the sequence AVGLLAPPGGLSGRSDNP (SEQ IDNO: 917), which is also referred to herein as substrate 3011. In someembodiments, the CM1-CM2 substrate includes the sequenceAVGLLAPPGGLSGRSANP (SEQ ID NO: 918), which is also referred to herein assubstrate 3012. In some embodiments, the CM1-CM2 substrate includes thesequence AVGLLAPPGGLSGRSANI (SEQ ID NO: 919), which is also referred toherein as substrate 3013. In some embodiments, the CM1-CM2 substrateincludes the sequence ISSGLLSGRSDNI (SEQ ID NO: 920), which is alsoreferred to herein as substrate 2014. In some embodiments, the CM1-CM2substrate includes the sequence AVGLLAPPGGLSGRSDNI (SEQ ID NO: 921),which is also referred to herein as substrate 3014. In some embodiments,the CM1-CM2 substrate includes the sequence GLSGRSDNHGGAVGLLAPP (SEQ IDNO: 1009), which is also referred to herein as substrate 0001/LP′/1004,where LP′ as used in this CM1-CM2 substrate is the amino acid sequenceGG. In some embodiments, the CM1-CM2 substrate includes the sequenceGLSGRSDNHGGVHMPLGFLGP (SEQ ID NO: 1010), which is also referred toherein as substrate 0001/LP′/1003, where LP′ as used in this CM1-CM2substrate is the amino acid sequence GG.

In some embodiments, the CM is a substrate for at least two proteases.In some embodiments, each protease is selected from the group consistingof those shown in Table 12. In some embodiments, the CM is a substratefor at least two proteases, wherein one of the proteases is selectedfrom the group consisting of a MMP, a thrombin, a neutrophil elastase, acysteine protease, a uPA, a legumain and a matriptase and other serineproteases and the other protease is selected from the group consistingof those shown in Table 12. In some embodiments, the CM is a substratefor at least two proteases selected from the group consisting of a MMP,a thrombin, a neutrophil elastase, a cysteine protease, a uPA, alegumain and a matriptase and other serine proteases.

In some embodiments, the activatable antibody includes at least a firstCM and a second CM. In some embodiments, the first CM and the second CMare each polypeptides of no more than 15 amino acids long. In someembodiments, the first CM and the second CM in the activatable antibodyin the uncleaved state have the structural arrangement from N-terminusto C-terminus as follows: MM-CM1-CM2-AB or AB-CM2-CM1-MM. In someembodiments, at least one of the first CM and the second CM is apolypeptide that functions as a substrate for a protease selected fromthe group consisting of a MMP, a thrombin, a neutrophil elastase, acysteine protease, a uPA, a legumain, and a matriptase and other serineproteases. In some embodiments, the first CM is cleaved by a firstcleaving agent selected from the group consisting of a MMP, a thrombin,a neutrophil elastase, a cysteine protease, a uPA, a legumain, and amatriptase and other serine proteases in a target tissue and the secondCM is cleaved by a second cleaving agent in a target tissue. In someembodiments, the other protease is selected from the group consisting ofthose shown in Table 12. In some embodiments, the first cleaving agentand the second cleaving agent are the same protease selected from thegroup consisting of a MMP, a thrombin, a neutrophil elastase, a cysteineprotease, a uPA, a legumain, and a matriptase and other serineproteases, and the first CM and the second CM are different substratesfor the enzyme. In some embodiments, the first cleaving agent and thesecond cleaving agent are the same protease selected from the groupconsisting of those shown in Table 12. In some embodiments, the firstcleaving agent and the second cleaving agent are different proteases. Insome embodiments, the first cleaving agent and the second cleaving agentare co-localized in the target tissue. In some embodiments, the first CMand the second CM are cleaved by at least one cleaving agent in thetarget tissue.

In some embodiments, the activatable antibody is exposed to and cleavedby a protease such that, in the activated or cleaved state, theactivated antibody includes a light chain amino acid sequence thatincludes at least a portion of LP2 and/or CM sequence after the proteasehas cleaved the CM.

In some embodiments, the activatable antibody also includes an agentconjugated to the AB. In some embodiments, the agent conjugated to theAB or the AB of an activatable antibody is a therapeutic agent. In someembodiments, the agent is an antineoplastic agent. In some embodiments,the agent is a toxin or fragment thereof. As used herein, a fragment ofa toxin is a fragment that retains toxic activity. In some embodiments,the agent is conjugated to the AB via a cleavable linker. In someembodiments, the agent is conjugated to the AB via a linker thatincludes at least one CM1-CM2 substrate sequence. In some embodiments,the agent is conjugated to the AB via a noncleavable linker. In someembodiments, the agent is conjugated to the AB via a linker that iscleavable in an intracellular or lysosomal environment. In someembodiments, the agent is a microtubule inhibitor. In some embodiments,the agent is a nucleic acid damaging agent, such as a DNA alkylator, aDNA cleaving agent, a DNA cross-linker, or DNA intercalator, or otherDNA damaging agent. In some embodiments, the agent is an agent selectedfrom the group listed in Table 11. In some embodiments, the agent is adolastatin. In some embodiments, the agent is an auristatin orderivative thereof. In some embodiments, the agent is auristatin E or aderivative thereof. In some embodiments, the agent is monomethylauristatin E (MMAE). In some embodiments, the agent is monomethylauristatin D (MMAD). In some embodiments, the agent is a maytansinoid ormaytansinoid derivative. In some embodiments, the agent is DM1 or DM4.In some embodiments, the agent is a duocarmycin or derivative thereof.In some embodiments, the agent is a calicheamicin or derivative thereof.In some embodiments, the agent is a pyrrolobenzodiazepine. In someembodiments, the agent is a pyrrolobenzodiazepine dimer.

In some embodiments, the activatable antibody is conjugated to one ormore equivalents of an agent. In some embodiments, the activatableantibody is conjugated to one equivalent of the agent. In someembodiments, the activatable antibody is conjugated to two, three, four,five, six, seven, eight, nine, ten, or greater than ten equivalents ofthe agent. In some embodiments, the activatable antibody is part of amixture of activatable antibodies having a homogeneous number ofequivalents of conjugated agents. In some embodiments, the activatableantibody is part of a mixture of activatable antibodies having aheterogeneous number of equivalents of conjugated agents. In someembodiments, the mixture of activatable antibodies is such that theaverage number of agents conjugated to each activatable antibody isbetween zero to one, between one to two, between two and three, betweenthree and four, between four and five, between five and six, between sixand seven, between seven and eight, between eight and nine, between nineand ten, and ten and greater. In some embodiments, the mixture ofactivatable antibodies is such that the average number of agentsconjugated to each activatable antibody is one, two, three, four, five,six, seven, eight, nine, ten, or greater.

In some embodiments, the activatable antibody comprises one or moresite-specific amino acid sequence modifications such that the number oflysine and/or cysteine residues is increased or decreased with respectto the original amino acid sequence of the activatable antibody, thus insome embodiments correspondingly increasing or decreasing the number ofagents that can be conjugated to the activatable antibody, or in someembodiments limiting the conjugation of the agents to the activatableantibody in a site-specific manner. In some embodiments, the modifiedactivatable antibody is modified with one or more non-natural aminoacids in a site-specific manner, thus in some embodiments limiting theconjugation of the agents to only the sites of the non-natural aminoacids.

In some embodiments, the agent is an anti-inflammatory agent.

In some embodiments, the activatable antibody also includes a detectablemoiety. In some embodiments, the detectable moiety is a diagnosticagent.

In some embodiments, the activatable antibody also includes a signalpeptide. In some embodiments, the signal peptide is conjugated to theactivatable antibody via a spacer. In some embodiments, the spacer isconjugated to the activatable antibody in the absence of a signalpeptide. In some embodiments, the spacer is joined directly to the MM ofthe activatable antibody. In some embodiments, the spacer is joineddirectly to the MM of the activatable antibody in the structuralarrangement from N-terminus to C-terminus of spacer-MM-CM-AB. An exampleof a spacer joined directly to the N-terminus of MM of the activatableantibody is selected from the group consisting of QGQSGS (SEQ ID NO:923), GQSGS (SEQ ID NO: 1192); QSGS (SEQ ID NO: 1193); SGS (SEQ ID NO:1194); GS (SEQ ID NO: 1195); S; QGQSGQG (SEQ ID NO: 924); GQSGQG (SEQ IDNO: 395); QSGQG (SEQ ID NO: 925); SGQG (SEQ ID NO: 926); GQG (SEQ ID NO:927); QG (SEQ ID NO: 928); G; QGQSGQ (SEQ ID NO: 1196); GQSGQ (SEQ IDNO: 1197); QSGQ (SEQ ID NO: 1198); SGQ (SEQ ID NO: 1198); GQ (SEQ ID NO:1199); and Q. In some embodiments, the spacer includes at least theamino acid sequence QGQSGS (SEQ ID NO: 923). In some embodiments, thespacer includes at least the amino acid sequence GQSGS (SEQ ID NO:1192). In some embodiments, the spacer includes at least the amino acidsequence QSGS (SEQ ID NO: 1193). In some embodiments, the spacerincludes at least the amino acid sequence SGS (SEQ ID NO: 1194). In someembodiments, the spacer includes at least the amino acid sequence GS(SEQ ID NO: 1195). In some embodiments, the spacer includes at least theamino acid sequence S. In some embodiments, the spacer includes at leastthe amino acid sequence QGQSGQG (SEQ ID NO: 924). In some embodiments,the spacer includes at least the amino acid sequence GQSGQG (SEQ ID NO:395). In some embodiments, the spacer includes at least the amino acidsequence QSGQG (SEQ ID NO: 925). In some embodiments, the spacerincludes at least the amino acid sequence SGQG (SEQ ID NO: 926). In someembodiments, the spacer includes at least the amino acid sequence GQG(SEQ ID NO: 927). In some embodiments, the spacer includes at least theamino acid sequence QG (SEQ ID NO: 928). In some embodiments, the spacerincludes at least the amino acid sequence G. In some embodiments, thespacer includes at least the amino acid sequence QGQSGQ (SEQ ID NO:1196). In some embodiments, the spacer includes at least the amino acidsequence GQSGQ (SEQ ID NO: 1197). In some embodiments, the spacerincludes at least the amino acid sequence QSGQ (SEQ ID NO: 1198). Insome embodiments, the spacer includes at least the amino acid sequenceSGQ (SEQ ID NO: 1198). In some embodiments, the spacer includes at leastthe amino acid sequence GQ (SEQ ID NO: 1199). In some embodiments, thespacer includes at least the amino acid sequence Q. In some embodiments,the activatable antibody does not include a spacer sequence.

In some embodiments, the AB of the activatable antibody naturallycontains one or more disulfide bonds. In some embodiments, the AB can beengineered to include one or more disulfide bonds.

In some embodiments, the serum half-life of the activatable antibody islonger than that of the corresponding antibody, e.g., the pK of theactivatable antibody is longer than that of the corresponding antibody.In some embodiments, the serum half-life of the activatable antibody issimilar to that of the corresponding antibody. In some embodiments, theserum half-life of the activatable antibody is at least 15 days whenadministered to an organism. In some embodiments, the serum half-life ofthe activatable antibody is at least 12 days when administered to anorganism. In some embodiments, the serum half-life of the activatableantibody is at least 11 days when administered to an organism. In someembodiments, the serum half-life of the activatable antibody is at least10 days when administered to an organism. In some embodiments, the serumhalf-life of the activatable antibody is at least 9 days whenadministered to an organism. In some embodiments, the serum half-life ofthe activatable antibody is at least 8 days when administered to anorganism. In some embodiments, the serum half-life of the activatableantibody is at least 7 days when administered to an organism. In someembodiments, the serum half-life of the activatable antibody is at least6 days when administered to an organism. In some embodiments, the serumhalf-life of the activatable antibody is at least 5 days whenadministered to an organism. In some embodiments, the serum half-life ofthe activatable antibody is at least 4 days when administered to anorganism. In some embodiments, the serum half-life of the activatableantibody is at least 3 days when administered to an organism. In someembodiments, the serum half-life of the activatable antibody is at least2 days when administered to an organism. In some embodiments, the serumhalf-life of the activatable antibody is at least 24 hours whenadministered to an organism. In some embodiments, the serum half-life ofthe activatable antibody is at least 20 hours when administered to anorganism. In some embodiments, the serum half-life of the activatableantibody is at least 18 hours when administered to an organism. In someembodiments, the serum half-life of the activatable antibody is at least16 hours when administered to an organism. In some embodiments, theserum half-life of the activatable antibody is at least 14 hours whenadministered to an organism. In some embodiments, the serum half-life ofthe activatable antibody is at least 12 hours when administered to anorganism. In some embodiments, the serum half-life of the activatableantibody is at least 10 hours when administered to an organism. In someembodiments, the serum half-life of the activatable antibody is at least8 hours when administered to an organism. In some embodiments, the serumhalf-life of the activatable antibody is at least 6 hours whenadministered to an organism. In some embodiments, the serum half-life ofthe activatable antibody is at least 4 hours when administered to anorganism. In some embodiments, the serum half-life of the activatableantibody is at least 3 hours when administered to an organism.

In some embodiments, the activatable anti-PDL1 antibody and/orconjugated activatable anti-PDL1 antibody is monospecific. In someembodiments, the activatable anti-PDL1 antibody and/or conjugatedactivatable anti-PDL1 antibody is multispecific, e.g., by way ofnon-limiting example, bispecific or trifunctional. In some embodiments,the activatable anti-PDL1 antibody and/or conjugated activatableanti-PDL1 antibody is formulated as part of a pro-Bispecific T CellEngager (BITE) molecule, i.e., the BITE includes a masking moiety and acleavable moiety. In some embodiments, the activatable anti-PDL1antibody and/or conjugated activatable anti-PDL1 antibody is formulatedas part of a pro-Chimeric Antigen Receptor (CAR)-modified T cell,-modified NK cell, or other-modified immune effector cell. In someembodiments, an activatable anti-PDL1 antibody is formulated as part ofanother engineered receptor on an immune effector cell; i.e., thepro-CAR or other pro-engineered receptor includes a masking moiety and acleavable moiety.

In some embodiments, the activatable antibody or antigen-bindingfragment thereof is incorporated in a multispecific activatable antibodyor antigen-binding fragment thereof, where at least one arm of the multispecific activatable antibody specifically binds PDL1. In someembodiments, the activatable antibody or antigen-binding fragmentthereof is incorporated in a bispecific antibody or antigen-bindingfragment thereof, where at least one arm of the bispecific activatableantibody specifically binds PDL1.

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises a heavychain amino acid sequence selected from the group consisting of SEQ IDNO: 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46,48, 50, 52, 54, and 56. In some embodiments, at least one arm of themultispecific activatable antibody, e.g., a bispecific activatableantibody, comprises a light chain amino acid sequence comprising SEQ IDNO: 12 or SEQ ID NO: 58. In some embodiments, at least one arm of themultispecific activatable antibody, e.g., a bispecific activatableantibody, comprises a light chain amino acid sequence comprising SEQ IDNO: 12. In some embodiments, at least one arm of the multispecificactivatable antibody, e.g., a bispecific activatable antibody, comprisesa light chain amino acid sequence comprising SEQ ID NO: 58.

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, a heavy chain aminoacid sequence comprising an amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a light chainamino acid sequence comprising SEQ ID NO: 58.

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises a heavychain amino acid sequence comprising an amino acid sequence selectedfrom the group consisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, anda light chain amino acid sequence comprising SEQ ID NO: 12.

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises a heavychain amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to an amino acid sequence selected fromthe group consisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28, 30,32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, and 56. In someembodiments, at least one arm of the multispecific activatable antibody,e.g., a bispecific activatable antibody, comprises a light chain aminoacid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence of SEQ ID NO: 58. In someembodiments, at least one arm of the multispecific activatable antibody,e.g., a bispecific activatable antibody, comprises a light chain aminoacid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence of SEQ ID NO: 12. In someembodiments, at least one arm of the multispecific activatable antibody,e.g., a bispecific activatable antibody, comprises a heavy chain aminoacid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98% or 99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a light chainamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the amino acid sequence of SEQ ID NO: 58. In someembodiments, at least one arm of the multispecific activatable antibody,e.g., a bispecific activatable antibody, comprises a heavy chain aminoacid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98% or 99% identical to an amino acid sequence selected from the groupconsisting of SEQ ID NO: 46, 48, 50, 52, 54, and 56, and a light chainamino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%or 99% identical to the amino acid sequence of SEQ ID NO: 12.

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises the heavychain amino acid sequence of SEQ ID NO: 46 and the light chain aminoacid sequence of SEQ ID NO: 58. In some embodiments, at least one arm ofthe multispecific activatable antibody, e.g., a bispecific activatableantibody, comprises the heavy chain amino acid sequence of SEQ ID NO: 46and the light chain amino acid sequence of SEQ ID NO: 12.

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises a heavychain amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid of SEQ ID NO: 46. Insome embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises a lightchain amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO: 58.In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises a lightchain amino acid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98% or 99% identical to the amino acid sequence of SEQ ID NO: 12.In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises a heavychain amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98% or 99% identical to the amino acid sequence selected ofSEQ ID NO: 46, and a light chain amino acid that is at least 90%, 91%,92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the amino acidsequence of SEQ ID NO: 58. In some embodiments, at least one arm of themultispecific activatable antibody, e.g., a bispecific activatableantibody, comprises a heavy chain amino acid sequence that is at least90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to theamino acid sequence selected of SEQ ID NO: 46, and a light chain aminoacid that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%identical to the amino acid sequence of SEQ ID NO: 12.

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises acombination of a variable heavy chain complementarity determining region1 (VH CDR1, also referred to herein as CDRH1) sequence, a variable heavychain complementarity determining region 2 (VH CDR2, also referred toherein as CDRH2) sequence, a variable heavy chain complementaritydetermining region 3 (VH CDR3, also referred to herein as CDRH3)sequence, a variable light chain complementarity determining region 1(VL CDR1, also referred to herein as CDRL1) sequence, a variable lightchain complementarity determining region 2 (VL CDR2, also referred toherein as CDRL2) sequence, and a variable light chain complementaritydetermining region 3 (VL CDR3, also referred to herein as CDRL3)sequence, wherein at least one CDR sequence is selected from the groupconsisting of a VH CDR1 sequence shown in Table 16; a VH CDR2 sequenceshown in Table 16; a VH CDR3 sequence shown in Table 16; a VL CDR1sequence shown in Table 16; a VL CDR2 sequence shown in Table 16; and aVL CDR3 sequence shown in Table 16.

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises acombination of a VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein at least one CDR sequence is selected from the groupconsisting of a VH CDR1 sequence that includes a sequence that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identicalto a VH CDR1 sequence shown in Table 16; a VH CD2 sequence that includesa sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,99% or more identical to a VH CDR2 sequence shown in Table 16; a VH CDR3sequence that includes a sequence that is at least 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, 99% or more identical to a VH CDR3 sequenceshown in Table 16; a VL CDR1 sequence that includes a sequence that isat least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or moreidentical to a VL CDR1 sequence shown in Table 16; a VL CDR2 sequencethat includes a sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, 99% or more identical to a VL CDR2 sequence shown inTable 16; and a VL CDR3 sequence that includes a sequence that is atleast 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identicalto a VL CDR3 sequence shown in Table 16.

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises acombination of a VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein the combination is a combination of the six CDRsequences (VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2, and VL CDR3)shown in a single row in Table 16.

In some embodiments, the antibody comprises a heavy chain that comprisea combination of a VH CDR1 sequence, a VH CDR2 sequence, and a VH CDR3sequence, wherein the combination is a combination of the three heavychain CDR sequences (VH CDR1, VH CDR2, VH CDR3) shown in a single row inTable 16.

In some embodiments, at least one arm of the multispecific activatableantibody. e.g., a bispecific activatable antibody, comprises acombination of a VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein each CDR sequence in the combination comprises asequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,99% or more identical to the corresponding CDR sequence in a combinationof the six CDR sequences (VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2,and VL CDR3) shown in a single row in Table 16.

In some embodiments, the antibody comprises a heavy chain that comprisea combination of a VH CDR1 sequence, a VH CDR2 sequence, and a VH CDR3sequence, wherein each CDR sequence in the combination comprises asequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,99% or more identical to the corresponding CDR sequence in a combinationof three heavy chain CDR sequences (VH CDR1, VH CDR2, VH CDR3) shown ina single row in Table 16.

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises acombination of a VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein at least one CDR sequence is selected from the groupconsisting of a VL CDR1 sequence comprising RASQSISSYLN (SEQ ID NO:209); a VL CDR2 sequence comprising AASSLQS (SEQ ID NO: 215), a VL CDR3sequence comprising DNGYPST (SEQ ID NO: 228); a VH CDR1 sequencecomprising SYAMS (SEQ ID NO: 212); a VH CDR2 sequence comprisingSSIWRNGIVTVYADS (SEQ ID NO: 246); and a VH CDR3 sequence comprisingWSAAFDY (SEQ ID NO: 235).

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises acombination of a VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein the VH CDR2 sequence comprises SSIWRNGIVTVYADS (SEQ IDNO: 246). In some embodiments, at least one arm of the multispecificactivatable antibody, e.g., a bispecific activatable antibody, comprisesa combination of a VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein the VH CDR3 sequence comprises WSAAFDY (SEQ ID NO:235). In some embodiments, at least one arm of the multispecificactivatable antibody, e.g., a bispecific activatable antibody, comprisesa combination of a VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein the VH CDR2 sequence comprises SSIWRNGIVTVYADS (SEQ IDNO: 246), and the VH CDR3 sequence comprises WSAAFDY (SEQ ID NO: 235).

In some embodiments, at least one arm of the multispecific activatableantibody, e.g., a bispecific activatable antibody, comprises acombination of a VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3sequence, a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein the combination comprises a VL CDR1 sequencecomprising RASQSISSYLN (SEQ ID NO: 209); a VL CDR2 sequence comprisingAASSLQS (SEQ ID NO: 215); a VL CDR3 sequence comprising DNGYPST (SEQ IDNO: 228); a VH CDR1 sequence comprising SYAMS (SEQ ID NO: 212); a VHCDR2 sequence comprising SSIWRNGIVTVYADS (SEQ ID NO: 246); and a VH CDR3sequence comprising WSAAFDY (SEQ ID NO: 235).

In some embodiments, the anti-PDL1 antibodies, conjugated anti-PDL1antibodies, activatable anti-PDL1 antibodies and/or conjugatedactivatable anti-PDL1 antibodies described herein are used as soleactive agents. In some embodiments, the anti-PDL1 antibodies, conjugatedanti-PDL1 antibodies, activatable anti-PDL1 antibodies and/or conjugatedactivatable anti-PDL1 antibodies described herein are used inconjunction with one or more additional agents or a combination ofadditional agents. Suitable additional agents include currentpharmaceutical and/or surgical therapies for an intended application,such as, for example, cancer. For example, the anti-PDL1 antibodies,conjugated anti-PDL1 antibodies, activatable anti-PDL1 antibodies and/orconjugated activatable anti-PDL1 antibodies can be used in conjunctionwith an additional chemotherapeutic or anti-neoplastic agent.

In some embodiments, the additional agent(s) is a chemotherapeuticagent, such as a chemotherapeutic agent selected from the groupconsisting of docetaxel, paclitaxel, abraxane (i.e., albumin-conjugatedpaclitaxel), doxorubicin, oxaliplatin, carboplatin, cisplatin,irinotecan, and gemcitabine.

In some embodiments, the additional agent(s) is a checkpoint inhibitor,a kinase inhibitor, an agent targeting inhibitors in the tumormicroenvironment, and/or a T cell or NK agonist. In some embodiments,the additional agent(s) is radiation therapy, alone or in combinationwith another additional agent(s) such as a chemotherapeutic oranti-neoplastic agent. In some embodiments, the additional agent(s) is avaccine, an oncovirus, and/or a DC-activating agent such as, by way ofnon-limiting example, a toll-like receptor (TLR) agonist and/or α-CD40.In some embodiments, the additional agent(s) is a tumor-targetedantibody designed to kill the tumor via ADCC or via direct conjugationto a toxin (e.g., an antibody drug conjugate (ADC).

In some embodiments, the checkpoint inhibitor is an inhibitor of atarget selected from the group consisting of CTLA-4, LAG-3, PD1 (alsoreferred to as PD-1), PDL1, TIGIT, TIM-3, B7H4, and Vista. In someembodiments, the kinase inhibitor is selected from the group consistingof B-RAFi, MEKi, and Btk inhibitors, such as ibrutinib. In someembodiments, the kinase inhibitor is crizotinib. In some embodiments,the tumor microenvironment inhibitor is selected from the groupconsisting of an IDO inhibitor, an α-CSF1R inhibitor, an α-CCR4inhibitor, a TGF-beta, a myeloid-derived suppressor cell, or aT-regulatory cell. In some embodiments, the agonist is selected from thegroup consisting of Ox40, GITR, CD137, ICOS, CD27, and HVEM.

In some embodiments, the inhibitor is a CTLA-4 inhibitor. In someembodiments, the inhibitor is a LAG-3 inhibitor. In some embodiments,the inhibitor is a PD1 inhibitor. In some embodiments, the inhibitor isa PDL1 inhibitor. In some embodiments, the inhibitor is a TIGITinhibitor. In some embodiments, the inhibitor is a TIM-3 inhibitor. Insome embodiments, the inhibitor is a B7H4 inhibitor. In someembodiments, the inhibitor is a Vista inhibitor. In some embodiments,the inhibitor is a B-RAFi inhibitor. In some embodiments, the B-RAFiinhibitor is vemurafenib. In some embodiments, the inhibitor is a MEKiinhibitor. In some embodiments, the inhibitor is a Btk inhibitor. Insome embodiments, the inhibitor is ibrutinib. In some embodiments, theinhibitor is crizotinib. In some embodiments, the inhibitor is an IDOinhibitor. In some embodiments, the inhibitor is an α-CSF1R inhibitor.In some embodiments, the inhibitor is an α-CCR4 inhibitor. In someembodiments, the inhibitor is a TGF-beta. In some embodiments, theinhibitor is a myeloid-derived suppressor cell. In some embodiments, theinhibitor is a T-regulatory cell.

In some embodiments, the agonist is Ox40. In some embodiments, theagonist is GITR. In some embodiments, the agonist is CD137. In someembodiments, the agonist is ICOS. In some embodiments, the agonist isCD27. In some embodiments, the agonist is HVEM.

In some embodiments, the anti-PDL1 antibody, conjugated antibody,activatable antibody and/or conjugated activatable antibody isadministered before and/or during and/or after treatment in combinationwith one or more additional agents such as, for example, achemotherapeutic agent, an anti-inflammatory agent, and/or animmunosuppressive agent. In some embodiments, the anti-PDL1 antibody,conjugated anti-PDL1 antibody, activatable anti-PDL1 antibody and/orconjugated activatable anti-PDL1 antibody and the additional agent areformulated into a single therapeutic composition, and the anti-PDL1antibody, conjugated anti-PDL1 antibody, activatable anti-PDL1 antibodyand/or conjugated activatable anti-PDL1 antibody and additional agentare administered simultaneously. Alternatively, the anti-PDL1 antibody,conjugated anti-PDL1 antibody, activatable anti-PDL1 antibody and/orconjugated activatable anti-PDL1 antibody and additional agent areseparate from each other, e.g., each is formulated into a separatetherapeutic composition, and the anti-PDL1 antibody, conjugatedanti-PDL1 antibody, activatable anti-PDL1 antibody and/or conjugatedactivatable anti-PDL1 antibody and the additional agent are administeredsimultaneously, or the anti-PDL1 antibody, conjugated anti-PDL1antibody, activatable anti-PDL1 antibody and/or conjugated activatableanti-PDL1 antibody and the additional agent are administered atdifferent times during a treatment regimen. For example, the anti-PDL1antibody, conjugated anti-PDL1 antibody, activatable anti-PDL1 antibodyand/or conjugated activatable anti-PDL1 antibody is administered priorto the administration of the additional agent, the anti-PDL1 antibody,conjugated anti-PDL1 antibody, activatable anti-PDL1 antibody and/orconjugated activatable anti-PDL1 antibody is administered subsequent tothe administration of the additional agent, or the anti-PDL1 antibody,conjugated anti-PDL1 antibody, activatable anti-PDL1 antibody and/orconjugated activatable anti-PDL1 antibody and the additional agent areadministered in an alternating fashion. As described herein, theanti-PDL1 antibody, conjugated anti-PDL1 antibody, activatable anti-PDL1antibody and/or conjugated activatable anti-PDL1 antibody and additionalagent are administered in single doses or in multiple doses.

In some embodiments, the anti-PDL1 antibody, conjugated anti-PDL1antibody, activatable anti-PDL1 antibody and/or conjugated activatableanti-PDL1 antibody and the additional agent(s) are administeredsimultaneously. For example, the anti-PDL1 antibody, conjugatedanti-PDL1 antibody, activatable anti-PDL1 antibody and/or conjugatedactivatable anti-PDL1 antibody and the additional agent(s) can beformulated in a single composition or administered as two or moreseparate compositions. In some embodiments, the anti-PDL1 antibody,conjugated anti-PDL1 antibody, activatable anti-PDL1 antibody and/orconjugated activatable anti-PDL1 antibody and the additional agent(s)are administered sequentially, or the anti-PDL1 antibody, conjugatedanti-PDL1 antibody, activatable anti-PDL1 antibody and/or conjugatedactivatable anti-PDL1 antibody and the additional agent are administeredat different times during a treatment regimen.

In some embodiments, the anti-PDL1 antibody, conjugated anti-PDL1antibody, activatable anti-PDL1 antibody and/or conjugated activatableanti-PDL1 antibody is administered before and/or during and/or aftertreatment in combination with one or more additional agents such as, byway of non-limiting example, a chemotherapeutic agent, ananti-inflammatory agent, and/or an immunosuppressive agent, such as analkylating agent, an anti-metabolite, an anti-microtubule agent, atopoisomerase inhibitor, a cytotoxic antibiotic, and/or any othernucleic acid damaging agent. In some embodiments, the additional agentis a taxane, such as paclitaxel (e.g., Abraxane®). In some embodiments,the additional agent is an anti-metabolite, such as gemcitabine. In someembodiments, the additional agent is an alkylating agent, such asplatinum-based chemotherapy, such as carboplatin or cisplatin. In someembodiments, the additional agent is a targeted agent, such as a kinaseinhibitor, e.g., sorafenib or erlotinib. In some embodiments, theadditional agent is a targeted agent, such as another antibody, e.g., amonoclonal antibody (e.g., bevacizumab), a bispecific antibody, or amultispecific antibody. In some embodiments, the additional agent is aproteosome inhibitor, such as bortezomib or carfilzomib. In someembodiments, the additional agent is an immune modulating agent, such aslenolidominde or IL-2. In some embodiments, the additional agent isradiation. In some embodiments, the additional agent is an agentconsidered standard of care by those skilled in the art. In someembodiments, the additional agent is a chemotherapeutic agent well knownto those skilled in the art.

In some embodiments, the additional agent is another antibody orantigen-binding fragment thereof, another conjugated antibody orantigen-binding fragment thereof, another activatable antibody orantigen-binding fragment thereof and/or another conjugated activatableantibody or antigen-binding fragment thereof. In some embodiments theadditional agent is another antibody or antigen-binding fragmentthereof, another conjugated antibody or antigen-binding fragmentthereof, another activatable antibody or antigen-binding fragmentthereof and/or another conjugated activatable antibody orantigen-binding fragment thereof against the same target as the firstantibody or antigen-binding fragment thereof, the first conjugatedantibody or antigen-binding fragment thereof, activatable antibody orantigen-binding fragment thereof and/or a conjugated activatableantibody or antigen-binding fragment thereof, e.g., against PDL1. Insome embodiments the additional agent is another antibody orantigen-binding fragment thereof, another conjugated antibody orantigen-binding fragment thereof, another activatable antibody orantigen-binding fragment thereof and/or another conjugated activatableantibody or antigen-binding fragment thereof against a target differentthan the target of the first antibody or antigen-binding fragmentthereof, the first conjugated antibody or antigen-binding fragmentthereof, activatable antibody or antigen-binding fragment thereof and/ora conjugated activatable antibody or antigen-binding fragment thereof(i.e., target other than PDL1). In some embodiments, the additionalagent is a chimeric antigen receptor-modified T cell, -modified NK cellor other-modified immune effector cell or is another engineeredreceptor-modified immune effector cell. In some embodiments, theadditional agent is a pro-chimeric antigen receptor-modified T cell,-modified NK cell, or other-modified immune effector cell or is anotherpro-engineered receptor-modified immune effector cell.

As a non-limiting example, the antibody or antigen-binding fragmentand/or the AB of an activatable antibody is a binding partner for anytarget listed in Table 22. In some embodiments that additional agent isipilimumab, a CTLA4-binding fragment of ipilimumab, and/or an ipilimumabactivatable antibody.

TABLE 22 Exemplary Targets 1-92-LFA-3 Alpha-4 integrin Alpha-V integrinalpha4beta1 integrin alpha4beta7 integrin AGR2 Anti-Lewis-Y Apelin Jreceptor APRIL B7-H4 BAFF BTLA C5 complement C-242 CA9 CA19-9 (Lewis a)Carbonic anhydrase 9 CD2 CD3 CD6 CD9 CD11a CD19 CD20 CD22 CD24 CD25 CD27CD28 CD30 CD33 CD38 CD40 CD40L CD41 CD44 CD44v6 CD47 CD51 CD52 CD56 CD64CD70 CD71 CD74 CD80 CD81 CD86 CD95 CD117 CD125 CD132 (IL-2RG) CD133CD137 CD138 CD166 CD172A CD248 CDH6 CEACAM5 (CEA) CEACAM6 (NCA-90)CLAUDIN-3 CLAUDIN-4 cMet Collagen Cripto CSFR CSFR-1 CTLA-4 CTGF CXCL10CXCL13 CXCR1 CXCR2 CXCR4 CYR61 DL44 DLK1 DLL4 DPP-4 DSG1 EGFR EGFRviiiEndothelin B receptor (ETBR) ENPP3 EpCAM EPHA2 EPHB2 ERBB3 F protein ofRSV FAP FGF-2 FGF8 FGFR1 FGFR2 FGFR3 FGFR4 Folate receptor GAL3ST1 G-CSFG-CSFR GD2 GITR GLUT1 GLUT4 GM-CSF GM-CSFR GP IIb/IIIa receptors Gp130GPIIB/IIIA GPNMB GRP78 HER2/neu HGF hGH HVEM Hyaluronidase ICOS IFNalphaIFNbeta IFNgamma IgE IgE Receptor (FceRI) IGF IGF1R IL1B IL1R IL2 IL11IL12 IL12p40 IL-12R, IL-12Rbeta1 IL13 IL13R IL15 IL17 IL18 IL21 IL23IL23R IL27/IL27R (wsx1) IL29 IL-31R IL31/IL31R IL2R IL4 IL4R IL6, IL6RInsulin Receptor Jagged Ligands Jagged 1 Jagged 2 LAG-3 LIF-R Lewis XLIGHT LRP4 LRRC26 MCSP Mesothelin MRP4 MUC1 Mucin-16 (MUC16, CA-125)Na/K ATPase Neutrophil elastase NGF Nicastrin Notch Receptors Notch 1Notch 2 Notch 3 Notch 4 NOV OSM-R OX-40 PAR2 PDGF-AA PDGF-BB PDGFRalphaPDGFRbeta PD-1 PD-L1 PD-L2 Phosphatidyl-serine P1GF PSCA PSMA RAAG12RAGE SLC44A4 Sphingosine 1 Phosphate STEAP1 STEAP2 TAG-72 TAPA1 TGFbetaTIGIT TIM-3 TLR2 TLR4 TLR6 TLR7 TLR8 TLR9 TMEM31 TNFalpha TNFR TNFRS12ATRAIL-R1 TRAIL-R2 Transferrin Transferrin receptor TRK-A TRK-B uPAR VAP1VCAM-1 VEGF VEGF-A VEGF-B VEGF-C VEGF-D VEGFR1 VEGFR2 VEGFR3 VISTAWISP-1 WISP-2 WISP-3

As a non-limiting example, the antibody or antigen-binding fragmentand/or the AB of an activatable antibody is or is derived from anantibody listed in Table 23.

TABLE 23 Exemplary sources for Abs Antibody Trade Name (antibody name)Target Avastin ™ (bevacizumab) VEGF Lucentis ™ (ranibizumab) VEGFErbitux ™ (cetuximab) EGFR Vectibix ™ (panitumumab) EGFR Remicade ™(infliximab) TNFα Humira ™ (adalimumab) TNFα Tysabri ™ (natalizumab)Integrinα4 Simulect ™ (basiliximab) IL2R Soliris ™ (eculizumab)Complement C5 Raptiva ™ (efalizumab) CD11a Bexxar ™ (tositumomab) CD20Zevalin ™ (ibritumomab tiuxetan) CD20 Rituxan ™ (rituximab) CD20(Ocrelizumab) CD20 Arzerra ™ (ofatumumab) CD20 Gazyva ™ (Obinutuzumab)CD20 Zenapax ™ (daclizumab) CD25 Adcetris ™ (brentuximab vedotin) CD30Myelotarg ™ (gemtuzumab) CD33 Mylotarg ™ (gemtuzumab ozogamicin) CD33Campath ™ (alemtuzumab) CD52 ReoPro ™ (abiciximab) Glycoprotein receptorIIb/IIIa Xolair ™ (omalizumab) IgE Herceptin ™ (trastuzumab) Her2Kadcyla ™ (trastuzumab emtansine) Her2 Synagis ™ (palivizumab) F proteinof RSV (ipilimumab) CTLA-4 (tremelimumab) CTLA-4 Hu5c8 CD40L(pertuzumab) Her2-neu (ertumaxomab) CD3/Her2-neu Orencia ™ (abatacept)CTLA-4 (tanezumab) NGF (bavituximab) Phosphatidylserine (zalutumumab)EGFR (mapatumumab) EGFR (matuzumab) EGFR (nimotuzumab) EGFR ICR62 EGFRmAb 528 EGFR CH806 EGFR MDX-447 EGFR/CD64 (edrecolomab) EpCAM RAV12RAAG12 huJ591 PSMA Enbrel ™ (etanercept) TNF-R Amevive ™ (alefacept)1-92-LFA-3 Antril ™, Kineret ™ (ankinra) IL-1Ra GC1008 TGFbeta Notch,e.g., Notch 1 Jagged 1 or Jagged 2 (adecatumumab) EpCAM (figitumumab)IGF1R (tocilizumab) IL-6 receptor Stelara ™ (ustekinumab) IL-12/IL-23Prolia ™ (denosumab) RANKL

In some embodiments, the additional antibody or antigen binding fragmentthereof, conjugated antibody or antigen binding fragment thereof,activatable antibody or antigen binding fragment thereof, and/orconjugated activatable antibody or antigen binding fragment thereof is amonoclonal antibody, domain antibody, single chain, Fab fragment, aF(ab′)₂ fragment, a scFv, a scAb, a dAb, a single domain heavy chainantibody, or a single domain light chain antibody. In some embodiments,the additional antibody or antigen binding fragment thereof, conjugatedantibody or antigen binding fragment thereof, activatable antibody orantigen binding fragment thereof, and/or conjugated activatable antibodyor antigen binding fragment thereof is a mouse, other rodent, chimeric,humanized or fully human monoclonal antibody.

The disclosure also provides methods of producing an anti-PDL1 antibodyand/or activatable anti-PDL1 antibody polypeptide by culturing a cellunder conditions that lead to expression of the polypeptide, wherein thecell comprises an isolated nucleic acid molecule encoding an antibodyand/or an activatable antibody described herein, and/or vectors thatinclude these isolated nucleic acid sequences. The disclosure providesmethods of producing an antibody and/or activatable antibody byculturing a cell under conditions that lead to expression of theantibody and/or activatable antibody, wherein the cell comprises anisolated nucleic acid molecule encoding an antibody and/or anactivatable antibody described herein, and/or vectors that include theseisolated nucleic acid sequences.

The invention also provides a method of manufacturing activatableantibodies that in an activated state binds PDL1 by (a) culturing a cellcomprising a nucleic acid construct that encodes the activatableantibody under conditions that lead to expression of the activatableantibody, wherein the activatable antibody comprises a masking moiety(MM), a cleavable moiety (CM), and an antibody or an antigen bindingfragment thereof (AB) that specifically binds PDL1, (i) wherein the CMis a polypeptide that functions as a substrate for a protease; and (ii)wherein the CM is positioned in the activatable antibody such that, whenthe activatable antibody is in an uncleaved state, the MM interfereswith specific binding of the AB to PDL1 and in a cleaved state the MMdoes not interfere or compete with specific binding of the AB to PDL1;and (b) recovering the activatable antibody. Suitable AB, MM, and/or CMinclude any of the AB, MM, and/or CM disclosed herein.

In some embodiments, the activatable antibody in the uncleaved state hasthe structural arrangement from N-terminus to C-terminus as follows:MM-CM-AB or AB-CM-MM. In some embodiments, the activatable antibodycomprises a linking peptide between the MM and the CM. In someembodiments, the activatable antibody comprises a linking peptidebetween the CM and the AB. In some embodiments, the activatable antibodycomprises a first linking peptide (LP1) and a second linking peptide(LP2), and wherein the activatable antibody in the uncleaved state hasthe structural arrangement from N-terminus to C-terminus as follows:MM-LP1-CM-LP2-AB or AB-LP2-CM-LP1-MM. In some embodiments, theactivatable antibody in the uncleaved state has the structuralarrangement from N-terminus to C-terminus as follows:spacer-MM-LP1-CM-LP2-AB or AB-LP2-CM-LP1-MM-spacer. In some embodiments,the two linking peptides need not be identical to each other.

In some embodiments, at least one of LP1 or LP2 comprises an amino acidsequence selected from the group consisting of (GS)_(n), (GGS)_(n),(GSGGS)_(n) (SEQ ID NO: 191) and (GGGS)_(n) (SEQ ID NO: 192), where n isan integer of at least one.

In some embodiments, at least one of LP1 or LP2 comprises an amino acidsequence selected from the group consisting of GGSG (SEQ ID NO: 193),GGSGG (SEQ ID NO: 194), GSGSG (SEQ ID NO: 195), GSGGG (SEQ ID NO: 196),GGGSG (SEQ ID NO: 197), and GSSSG (SEQ ID NO: 198).

In some embodiments, LP1 comprises the amino acid sequence GSSGGSGGSGGSG(SEQ ID NO: 199), GSSGGSGGSGG (SEQ ID NO: 200), GSSGGSGGSGGS (SEQ ID NO:201), GSSGGSGGSGGSGGGS (SEQ ID NO: 202), GSSGGSGGSG (SEQ ID NO: 203), orGSSGGSGGSGS (SEQ ID NO: 204).

In some embodiments, LP2 comprises the amino acid sequence GSS, GGS,GGGS (SEQ ID NO: 205), GSSGT (SEQ ID NO: 206) or GSSG (SEQ ID NO: 207).

The invention provides methods of preventing, delaying the progressionof, treating, alleviating a symptom of, or otherwise ameliorating anPDL1 mediated disease in a subject by administering a therapeuticallyeffective amount of an anti-PDL1 antibody, conjugated anti-PDL1antibody, activatable anti-PDL1 antibody and/or conjugated activatableanti-PDL1 antibody described herein to a subject in need thereof.

The invention also provides methods of preventing, delaying theprogression of, treating, alleviating a symptom of, or otherwiseameliorating cancer in a subject by administering a therapeuticallyeffective amount of an anti-PDL1 antibody, conjugated anti-PDL1antibody, activatable anti-PDL1 antibody and/or conjugated activatableanti-PDL1 antibody described herein to a subject in need thereof. PDL1is known to be expressed in a variety of cancers, such as, by way ofnon-limiting example, melanoma, non-small cell lung cancer,nasopharyngeal cancer, glioblastoma/mixed glioma, colon adenocarcinoma,hepatocellular carcinoma, urothelial cancer, multiple myeloma, ovariancancer, gastric carcinoma, esophageal cancer, pancreatic cancer, renalcell carcinoma (RCC), breast cancer, lymphomas, and leukemias. (Seee.g., Chen et al., “Molecular Pathways: Next-GenerationImmunotherapy—Inhibiting Programmed Death-Ligand 1 and ProgrammedDeath-1,” Clin. Can. Res., vol. 18: 6580-6587 (2012), the contents ofwhich are hereby incorporated by reference in their entirety).

In some embodiments, the cancer is a bladder cancer, a bone cancer, abreast cancer, a carcinoid, a cervical cancer, a colon cancer, anendometrial cancer, a glioma, a head and neck cancer, a liver cancer, alung cancer, a lymphoma, a melanoma, an ovarian cancer, a pancreaticcancer, a prostate cancer, a renal cancer, a sarcoma, a skin cancer, astomach cancer, a testis cancer, a thyroid cancer, a urogenital cancer,and/or a urothelial cancer.

In some embodiments, the cancer is selected from the group consisting ofmelanoma (MEL), renal cell carcinoma (RCC), squamous non-small cell lungcancer (NSCLC), non-squamous NSCLC, colorectal cancer (CRC),castration-resistant prostate cancer (CRPC), hepatocellular carcinoma(HCC), squamous cell carcinoma of the head and neck, carcinomas of theesophagus, ovary, gastrointestinal tract and breast, or a hematologicmalignancy such as multiple myeloma, B-cell lymphoma, T-cell lymphoma,Hodgkin's lymphoma/primary mediastinal B-cell lymphoma, and chronicmyelogenous leukemia. In some embodiments, the cancer is due to aPDL1-expressing tumor.

The invention also provides methods of treating cancer patients with anautoimmune or inflammatory disease by administering a therapeuticallyeffective amount of an anti-PDL1 antibody, conjugated anti-PDL1antibody, activatable anti-PDL1 antibody and/or conjugated activatableanti-PDL1 antibody described herein to a subject in need thereof. Insome embodiments, the autoimmune disease is colitis, RA, pancreatitis,diabetes, or pneumonitis.

An anti-PDL1 antibody, a conjugated anti-PDL1 antibody, an activatableanti-PDL1 antibody and/or a conjugated activatable anti-PDL1 antibodyused in any of the embodiments of these methods and uses can beadministered at any stage of the disease. For example, such an anti-PDL1antibody, conjugated anti-PDL1 antibody, activatable anti-PDL antibodyand/or conjugated activatable anti-PDL1 antibody can be administered toa patient suffering cancer of any stage, from early to metastatic. Theterms subject and patient are used interchangeably herein.

In some embodiments, the subject is a mammal, such as a human, non-humanprimate, companion animal (e.g., cat, dog, horse), farm animal, workanimal, or zoo animal. In some embodiments, the subject is a human. Insome embodiments, the subject is a companion animal. In someembodiments, the subject is an animal in the care of a veterinarian.

The anti-PDL1 antibody, conjugated anti-PDL1 antibody, activatableanti-PDL1 antibody and/or conjugated activatable anti-PDL1 antibody andtherapeutic formulations thereof are administered to a subject sufferingfrom or susceptible to a disease or disorder associated with aberrantPDL1 expression and/or activity. A subject suffering from or susceptibleto a disease or disorder associated with aberrant PDL1 expression and/oractivity is identified using any of a variety of methods known in theart. For example, subjects suffering from cancer or other neoplasticcondition are identified using any of a variety of clinical and/orlaboratory tests such as, physical examination and blood, urine and/orstool analysis to evaluate health status. For example, subjectssuffering from inflammation and/or an inflammatory disorder areidentified using any of a variety of clinical and/or laboratory testssuch as physical examination and/or bodily fluid analysis, e.g., blood,urine and/or stool analysis, to evaluate health status.

Administration of an anti-PDL1 antibody, conjugated anti-PDL1 antibody,activatable anti-PDL1 antibody and/or conjugated activatable anti-PDL1antibody to a patient suffering from a disease or disorder associatedwith aberrant PDL1 expression and/or activity is considered successfulif any of a variety of laboratory or clinical objectives is achieved.For example, administration of an anti-PDL1 antibody, conjugatedanti-PDL1 antibody, activatable anti-PDL1 antibody and/or conjugatedactivatable anti-PDL1 antibody to a patient suffering from a disease ordisorder associated with aberrant PDL1 expression and/or activity isconsidered successful if one or more of the symptoms associated with thedisease or disorder is alleviated, reduced, inhibited or does notprogress to a further, i.e., worse, state. Administration of ananti-PDL1 antibody, conjugated anti-PDL1 antibody, activatable anti-PDL1antibody and/or conjugated activatable anti-PDL1 antibody to a patientsuffering from a disease or disorder associated with aberrant PDL1expression and/or activity is considered successful if the disease ordisorder enters remission or does not progress to a further, i.e.,worse, state.

In some embodiments, the anti-PDL1 antibody, conjugated anti-PDL1antibody, activatable anti-PDL1 antibody and/or conjugated activatableanti-PDL1 antibody is administered before and/or during and/or aftertreatment in combination with one or more additional agents such as, forexample, a chemotherapeutic agent, an anti-inflammatory agent, and/or animmunosuppressive agent. In some embodiments, the anti-PDL1 antibody,conjugated anti-PDL1 antibody, activatable anti-PDL1 antibody and/orconjugated activatable anti-PDL1 antibody and the additional agent(s)are administered simultaneously. For example, the anti-PDL1 antibody,conjugated anti-PDL1 antibody, activatable anti-PDL1 antibody and/orconjugated activatable anti-PDL1 antibody and the additional agent(s)can be formulated in a single composition or administered as two or moreseparate compositions. In some embodiments, the anti-PDL1 antibody,conjugated anti-PDL1 antibody, activatable anti-PDL1 antibody and/orconjugated activatable anti-PDL1 antibody and the additional agent(s)are administered sequentially.

The invention also provides methods and kits for using the activatableanti-PDL1 antibodies and/or conjugated activatable anti-PDL1 antibodiesin a variety of diagnostic and/or prophylactic indications. For example,the invention provides methods and kits for detecting the presence orabsence of a cleaving agent and a target of interest in a subject or asample by (i) contacting a subject or sample with an anti-PDL1activatable antibody, wherein the anti-PDL1 activatable antibodycomprises a masking moiety (MM), a cleavable moiety (CM) that is cleavedby the cleaving agent, and an antigen binding domain or fragment thereof(AB) that specifically binds the target of interest, wherein theanti-PDL1 activatable antibody in an uncleaved, non-activated statecomprises a structural arrangement from N-terminus to C-terminus asfollows: MM-CM-AB or AB-CM-MM; (a) wherein the MM is a peptide thatinhibits binding of the AB to PDL1, and wherein the MM does not have anamino acid sequence of a naturally occurring binding partner of the ABand is not a modified form of a natural binding partner of the AB; and(b) wherein, when the AB is in an uncleaved, non-activated state, the MMinterferes with specific binding of the AB to PDL1, and when the AB isin a cleaved, activated state the MM does not interfere or compete withspecific binding of the AB to PDL1; and (ii) measuring a level ofactivated anti-PDL1 activatable antibody in the subject or sample,wherein a detectable level of activated anti-PDL1 activatable antibodyin the subject or sample indicates that the cleaving agent and PDL1 arepresent in the subject or sample and wherein no detectable level ofactivated anti-PDL1 activatable antibody in the subject or sampleindicates that the cleaving agent, PDL1 or both the cleaving agent andPDL1 are absent in the subject or sample.

In some embodiments, the activatable anti-PDL1 antibody is anactivatable anti-PDL1 antibody to which a therapeutic agent isconjugated. In some embodiments, the activatable anti-PDL1 antibody isnot conjugated to an agent. In some embodiments, the activatableanti-PDL1 antibody comprises a detectable label. In some embodiments,the detectable label is positioned on the AB. In some embodiments,measuring the level of activatable anti-PDL1 antibody in the subject orsample is accomplished using a secondary reagent that specifically bindsto the activated antibody, wherein the reagent comprises a detectablelabel. In some embodiments, the secondary reagent is an antibodycomprising a detectable label.

In some embodiments of these methods and kits, the activatable anti-PDL1antibody includes a detectable label. In some embodiments of thesemethods and kits, the detectable label includes an imaging agent, acontrasting agent, an enzyme, a fluorescent label, a chromophore, a dye,one or more metal ions, or a ligand-based label. In some embodiments ofthese methods and kits, the imaging agent comprises a radioisotope. Insome embodiments of these methods and kits, the radioisotope is indiumor technetium. In some embodiments of these methods and kits, thecontrasting agent comprises iodine, gadolinium or iron oxide. In someembodiments of these methods and kits, the enzyme comprises horseradishperoxidase, alkaline phosphatase, or β-galactosidase. In someembodiments of these methods and kits, the fluorescent label comprisesyellow fluorescent protein (YFP), cyan fluorescent protein (CFP), greenfluorescent protein (GFP), modified red fluorescent protein (mRFP), redfluorescent protein tdimer2 (RFP tdimer2), HCRED, or a europiumderivative. In some embodiments of these methods and kits, theluminescent label comprises an N-methylacrydium derivative. In someembodiments of these methods, the label comprises an Alexa Fluor® label,such as Alex Fluor® 680 or Alexa Fluor® 750. In some embodiments ofthese methods and kits, the ligand-based label comprises biotin, avidin,streptavidin or one or more haptens.

In some embodiments of these methods and kits, the subject is a mammal.In some embodiments of these methods, the subject is a human. In someembodiments, the subject is a non-human mammal, such as a non-humanprimate, companion animal (e.g., cat, dog, horse), farm animal, workanimal, or zoo animal. In some embodiments, the subject is a rodent.

In some embodiments of these methods and kits, the method is an in vivomethod. In some embodiments of these methods, the method is an in situmethod. In some embodiments of these methods, the method is an ex vivomethod. In some embodiments of these methods, the method is an in vitromethod.

In some embodiments of the methods and kits, the method is used toidentify or otherwise refine a patient population suitable for treatmentwith an anti-PDL1 activatable antibody of the disclosure, followed bytreatment by administering that activatable anti-PDL1 antibody and/orconjugated activatable anti-PDL1 antibody to a subject in need thereof.For example, patients that test positive for both the target (e.g.,PDL1) and a protease that cleaves the substrate in the cleavable moiety(CM) of the anti-PDL1 activatable antibody being tested in these methodsare identified as suitable candidates for treatment with such ananti-PDL1 activatable antibody comprising such a CM, and the patient isthen administered a therapeutically effective amount of the activatableanti-PDL1 antibody and/or conjugated activatable anti-PDL1 antibody thatwas tested. Likewise, patients that test negative for either or both ofthe target (e.g., PDL1) and the protease that cleaves the substrate inthe CM in the activatable antibody being tested using these methodsmight be identified as suitable candidates for another form of therapy.In some embodiments, such patients can be tested with other anti-PDL1activatable antibodies until a suitable anti-PDL1 activatable antibodyfor treatment is identified (e.g., an anti-PDL1 activatable antibodycomprising a CM that is cleaved by the patient at the site of disease).In some embodiments, the patient is then administered a therapeuticallyeffective amount of the activatable anti-PDL1 antibody and/or conjugatedfor which the patient tested positive. Suitable AB, MM, and/or CMinclude any of the AB, MM, and/or CM disclosed herein.

Pharmaceutical compositions according to the invention can include anantibody of the invention and a carrier. These pharmaceuticalcompositions can be included in kits, such as, for example, diagnostickits.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is graph depicting by ELISA-based binding that PDL1 c60ScFv-phage binds specifically to human and mouse PDL1.

FIG. 2A is a graph depicting that hPD1 inhibits the binding of clones12, 18 and 60 to hPDL1 in an ELISA format, and, furthermore mPD1inhibits the binding of clone 60 to mPDL1.

FIG. 3A is a graph depicting saturation binding data and demonstratesthat anti-PDL1 clone 60:IgG binds to human PDL1 with a bindingaffinity˜1 nM, and to mouse PDL1 at 30 nM.

FIGS. 4A and 4B are a series of graphs depicting H2 specificity andcross reactivity (FIG. 4A) and H3W specificity and cross reactivity(FIG. 4B).

FIGS. 5A and 5B are a series of graphs depicting that combining thematured heavy variable CDR3 domains with the heavy variable CDR2 domainsresults in antibodies with enhanced affinity towards human PDL1.

FIGS. 6A, 6B, 6C, and 6D are a series of graphs depicting that anti-PDL1antibody C5H9 binds to human and mouse PDL1 with near equal affinity andthat anti-PDL1 antibodies C5B10 and C5E10 only bind human PDL1.

FIG. 7A is a graph depicting the ability of anti-PDL1 antibody C5H9 tobind with high and equal affinity to human, mouse and cyno PDL1.

FIGS. 8A and 8B are a series of graphs depicting that anti-PDL1 antibodyC5H9v2 has lower immunogenicity potential and enhancedmanufacturability. These graphs demonstrate decreased predictedimmunogenicity, increased expression levels (3×), and increased monomerpercentage in human IgG1 format.

FIGS. 9A, 9B, and 9C are a series of graphs depicting ability ofanti-PDL1 antibody C5H9v2 to bind with high affinity to (A) mouse, (B)cyno, and (C) human PDL1. FIGS. 9A-9C show that both anti-PDL1antibodies C5H9 and C5H9v2 bind human, mouse and cyno PDL1 with nearequal affinities.

FIG. 10A is a graph depicting C5H9v2 specificity for a panel of humanand mouse proteins. FIG. 10A demonstrates that anti-PDL1 antibody C5H9v2binds only to human and mouse PDL1 demonstrating specificity towardPDL1.

FIG. 11A is a series of graphs depicting B7-1 and PD1 blockade. FIG. 11demonstrates that both anti-PDL1 antibody C5H9 and anti-PDL1 antibodyC5H9v2 are potent blockers of either B7-1 or PD1 binding to PDL1, andthat blockade includes all three species human, cyno and mouse withsingle digit nM EC₅₀'s.

FIG. 12A is a graph depicting that anti-PDL1 antibody C5H9 acceleratesthe onset of diabetes in NOD mice similar to the positive controlanti-PDL1 antibody 10F9G2.

FIG. 13A is a graph depicting that anti-PDL1 antibody C5H9v2 acceleratesthe onset of diabetes in NOD mice in a dose dependent matter.

FIG. 14A is a graph depicting that an anti-PDL1 antibody C5H9v2 inhibitsthe growth of MC38 syngeneic tumors similar to positive controlanti-PDL1 antibody 10F9G2.

FIGS. 15A and B are a series of graphs depicting binding isotherms foranti-PDL1 activatable antibodies that include the anti-PDL1 antibodyC5H9v2.

FIG. 16A is a graph depicting binding isotherms for anti-PDL1activatable antibodies that include the anti-PDL1 antibody C5H9v2.

FIG. 17A is a graph depicting binding isotherms for anti-PDL1activatable antibodies that include the anti-PDL1 antibody C5H9v2.

FIGS. 18A and 18B are a series of graphs depicting that anti-PDL1activatable antibody PL15-0003-C5H9v2, when administered at a dose of 1mg/kg, has an absence of diabetes induction and anti-PDL1 activatableantibody PL18-0003-C5H9v2, when administered at a dose of 1 mg/kg, has adelay in diabetes induction compared to the anti-PDL1 antibody C5H9v2administered at a dose of 1 mg/kg in NOD mice (FIG. 18A); in addition,anti-PDL1 activatable antibody PL15-0003-C5H9v2, when administered at adose of 3 mg/kg induced diabetes in 2 of 8 NOD mice (75% non-diabetic),compared to 1 mg/kg anti-PDL1 antibody C5H9v2 which led to 38%non-diabetic NOD mice (FIG. 18B).

FIG. 19A is a graph depicting that anti-PDL1 activatable antibodiesPL15-0003-C5H9v2 and PL18-0003-C5H9v2 inhibit the growth of MC38syngeneic tumors similar to anti-PDL1 antibody C5H9v2.

FIGS. 20A, 20B, 20C, and 20D are a series of graphs depicting thepercent of anti-PDL1 antibody C5H9v2 and anti-PDL1 activatable antibodyPL15-0003-C5H9v2 bound to CD4+ and CD8+ T cells from peripheral blood(FIGS. 20A, 20B) or spleen (FIGS. 20C, 20D). In all graphs, the circlerepresents isotype, the square represents anti-PDL1 antibody C5H9v2, andthe triangle represents anti-PDL1 activatable antibody PL15-0003-C5H9v2.

FIGS. 21A and 21B are a series of graphs depicting that the presence oftumor-derived proteases capable of cleaving anti-PDL1 activatableantibody PL15-0003-C5H9v2 (depicted by squares) did not lead to highlevels of activated activatable antibody in the blood compared toanti-PDL1 antibody C5H9v2 (depicted by circles) or an isotype antibody(depicted by triangles) (FIG. 21A) despite the plasma concentrations ofthe activatable antibody being higher than those of the antibody (FIG.21B).

FIG. 22A is a graph depicting the ability of anti-PDL1 activatableantibody PL07-2001-C5H9v2 to increase CMV-stimulated IFN-gamma secretionas compared to control hIgG4, but with decreased potency relative toanti-PDL1 parental antibody C5H9v2.

FIGS. 23A, 23B, 23C, and 23D are a series of images showing the abilityof anti-PDL1 activatable antibody PL15-0003-C5H9v2 to be activated andto bind frozen MC38 mouse cancer tissues using an in situ imagingmethod.

FIG. 24A depicts that anti-PDL1 activatable antibody PL15-0003-C5H9v2exhibited a higher EC₅₀ for PDL1 binding and PD1 blocking than did theanti-PDL1 antibody as measured by ELISA. The figure further demonstratesthat activation of anti-PDL1 activatable antibody PL15-0003-C5H9v2 bymatriptase fully restored PDL1 binding and PD1 blocking activities tolevels comparable to those of anti-PDL1 antibody C5H9v2.

FIGS. 25A and 25B are a series of graphs depicting the ability ofanti-PDL1 activatable antibodies referred to herein as PL07-2001-C5H9v2and PF07-3001-C5H9v2 and of the anti-PDL1 antibody referred to herein asC5H9 to bind to human or murine PDL1.

FIGS. 26A, 26B, and 26C are a series of graphs depicting the abilitiesof anti-PDL1 activatable antibody PL07-2001-C5H9v2, uPA-activatedanti-PDL1 activatable antibody PL07-2001-C5H9v2, MMP14-activatedanti-PDL1 activatable antibody PL07-2001-C5H9v2, and anti-PDL1 antibodyC5H9v2 to block human PD1 (PD-1) to human PDL1 (FIG. 26A), cynomolgusPD1 (PD-1) binding to cynomolgus PDL1 (FIG. 26B), or rat PD1 (PD-1)binding to rat PDL1 (FIG. 26C).

FIGS. 27A and 27B are a series of graphs depicting the ability ofanti-PDL1 activatable antibody PL07-2001-C5H9v2, uPA-activated anti-PDL1activatable antibody PL07-2001-C5H9v2, MMP14-activated anti-PDL1activatable antibody PL07-2001-C5H9v2, or anti-PDL1 antibody C5H9v2 tohuman B7-1 binding to human PDL1 (FIG. 27A) or cynomolgus B7-1 bindingto cynomolgus PDL1 (FIG. 27B).

FIG. 28A is a graph depicting the ability of the anti-PDL1 activatableantibodies PL15-0003-C5H9v2, PL15-2001-C5H9v2, and PL15-3001-C5H9v2 toinhibit the growth of MC38 syngeneic tumors similar to positive controlanti-PDL1 antibody C5H9v2.

FIGS. 29A, 29B, and 29C are a series of graphs depicting that thepresence of tumor-derived proteases capable of cleaving the activatableantibodies anti-PDL1 antibody C5H9v2 or anti-PDL1 activatable antibodyPL15-0003-C5H9v2, PL15-2001-C5H9v2, or PL15-3001-C5H9v2 did not lead tohigh levels of activated activatable antibodies in the blood.

FIG. 30A is an illustration depicting the ability of proteases in atumor implanted into a mouse to activate the anti-PDL1 activatableantibody PL07-2001-C5H9v2.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides monoclonal antibodies (mAbs) andactivatable monoclonal antibodies that specifically bind humanprogrammed death ligand 1 (PDL1). PDL1 is a 40 kDa type I transmembraneprotein that forms a complex with its receptor programmed cell deathprotein 1 (PD1), also known as CD279. Engagement of PDL1 with itsreceptor PD1 on T cells delivers a signal that inhibits TCR-mediatedactivation of IL-2 production and T cell proliferation. Aberrantexpression and/or activity of PDL1 and PDL1-related signaling has beenimplicated in the pathogenesis of many diseases and disorders, such ascancer, inflammation, and autoimmunity.

The activatable anti-PDL1 antibodies are used in methods of treating,preventing, delaying the progression of, ameliorating and/or alleviatinga symptom of a disease or disorder associated with aberrant PDL1expression and/or activity. For example, the activatable anti-PDL1antibodies are used in methods of treating, preventing, delaying theprogression of, ameliorating and/or alleviating a symptom of a cancer orother neoplastic condition.

The activatable anti-PDL1 antibodies include an antibody orantigen-binding fragment thereof that specifically binds PDL1 coupled toa masking moiety (MM), such that coupling of the MM reduces the abilityof the antibody or antigen-binding fragment thereof to bind PDL1. Insome embodiments, the MM is coupled via a sequence that includes asubstrate for a protease, for example, a protease that is co-localizedwith PDL1 at a treatment site in a subject.

Exemplary activatable anti-PDL1 antibodies of the invention include, forexample, activatable antibodies that include a heavy chain and a lightchain that are, or are derived from, antibodies described in theExamples, for example in Example 3 and Example 4.

In some embodiments, the activatable anti-PDL1 antibody includes a heavychain that comprises or is derived from an amino acid sequence selectedfrom the group consisting of SEQ ID NO: 14, 16, 18, 20, 22, 24, 26, 28,30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, and 56, and a lightchain that comprises or is derived from the amino acid sequence of SEQID NO: 12 or SEQ ID NO: 58.

In some embodiments, the activatable anti-PDL1 antibody comprises acombination of a variable heavy chain complementarity determining region1 (VH CDR1, also referred to herein as CDRH1) sequence, a variable heavychain complementarity determining region 2 (VH CDR2, also referred toherein as CDRH2) sequence, a variable heavy chain complementaritydetermining region 3 (VH CDR3, also referred to herein as CDRH3)sequence, a variable light chain complementarity determining region 1(VL CDR1, also referred to herein as CDRL1) sequence, a variable lightchain complementarity determining region 2 (VL CDR2, also referred toherein as CDRL2) sequence, and a variable light chain complementaritydetermining region 3 (VL CDR3, also referred to herein as CDRL3)sequence, wherein at least one CDR sequence is selected from the groupconsisting of a VH CDR1 sequence shown in Table 15; a VH CDR2 sequenceshown in Table 15; a VH CDR3 sequence shown in Table 15; a VL CDR1sequence shown in Table 15; a VL CDR2 sequence shown in Table 15; and aVL CDR3 sequence shown in Table 15.

In some embodiments, the activatable antibody comprises a combination ofa VH CDR1 sequence, a VH CDR2 sequence, a VH CDR3 sequence, a VL CDR1sequence, a VL CDR2 sequence, and a VL CDR3 sequence, wherein thecombination is a combination of the six CDR sequences (VH CDR1, VH CDR2,VH CDR3, VL CDR1, VL CDR2, and VL CDR3) shown in a single row in Table15.

In some embodiments, the antibody comprises a heavy chain that comprisea combination of a VH CDR1 sequence, a VH CDR2 sequence, and a VH CDR3sequence, wherein the combination is a combination of the three heavychain CDR sequences (VH CDR1, VH CDR2, VH CDR3) shown in a single row inTable 15.

In some embodiments, the antibody comprises a light chain that comprisea combination of a VL CDR1 sequence, a VL CDR2 sequence, and a VL CDR3sequence, wherein the combination is a combination of the three lightchain CDR sequences (VL CDR1, VL CDR2, VL CDR3) shown in a single row inTable 15.

In some embodiments, the activatable anti-PDL1 antibody includes a heavychain that comprises or is derived from a heavy chain amino acidsequence shown in Table 15. In some embodiments, the activatableanti-PDL1 antibody includes a light chain that comprises or is derivedfrom a light chain amino acid sequence shown in Table 15. In someembodiments, the activatable anti-PDL1 antibody includes a heavy chainthat comprises or is derived from a heavy chain amino acid sequenceshown in Table 15, and a light chain that comprises or is derived from alight chain amino acid sequence shown in Table 15. In some embodiments,the activatable anti-PDL1 antibody includes a combination of heavy chainvariable region and light chain variable region sequences from thecombinations shown in Group A in Table 15. In some embodiments, theactivatable anti-PDL1 antibody includes the combination of heavy chainvariable region and light chain variable region sequences shown in GroupB in Table 15. In some embodiments, the activatable anti-PDL1 antibodyincludes the combination of heavy chain variable region and light chainvariable region sequences shown in Group C in Table 15. In someembodiments, the activatable anti-PDL1 antibody includes the combinationof heavy chain variable region and light chain variable region sequencesshown in Group D in Table 15. In some embodiments, the activatableanti-PDL1 antibody includes the combination of heavy chain variableregion and light chain variable region sequences shown in Group E inTable 15. In some embodiments, the activatable anti-PDL1 antibodyincludes the combination of heavy chain variable region and light chainvariable region sequences shown in Group F in Table 15. In someembodiments, the activatable anti-PDL1 antibody includes the combinationof heavy chain variable region and light chain variable region sequencesshown in Group G in Table 15. In some embodiments, the activatableanti-PDL1 antibody includes the combination of heavy chain variableregion and light chain variable region sequences shown in Group H inTable 15. In some embodiments, the activatable anti-PDL1 antibodyincludes the combination of heavy chain variable region and light chainvariable region sequences shown in Group I in Table 15. In someembodiments, the activatable anti-PDL1 antibody includes the combinationof heavy chain and light chain sequences shown in Group J in Table 15.In some embodiments, the activatable anti-PDL1 antibody includes thecombination of heavy chain variable region and light chain variableregion sequences shown in Group K in Table 15. In some embodiments, theactivatable anti-PDL1 antibody includes the combination of heavy chainand light chain sequences shown in Group K in Table 15. In someembodiments, the activatable anti-PDL1 antibody includes the combinationof heavy chain variable region and light chain variable region sequencesshown in Group L in Table 15. In some embodiments, the activatableanti-PDL1 antibody includes the combination of heavy chain variableregion and light chain variable region sequences shown in Group M inTable 15. In some embodiments, the activatable anti-PDL1 antibodyincludes the combination of heavy chain variable region and light chainvariable region sequences shown in Group N in Table 15. In someembodiments, the activatable anti-PDL1 antibody includes the combinationof heavy chain variable region and light chain variable region sequencesshown in Group O in Table 15.

TABLE 15Variable Heavy Chain Region (VH) and Variable Light Chain Region (VL)Sequences for Activatable Antibodies that Bind PDL1 (CDR sequences areunderlined; CDR sequences disclosed herein were identified in accordance withthe definitions of Kabat, Sequences of Proteins of Immunological Interest(National Institutes of Health, Bethesda, Md. (1987 and 1991))) Group AVHQVQLVQSGAEVKKPGASVKVSCKASGYTFTDYGFSWVRQAPGQGLEWMGWITAYNGNTNYAQKLQGRVTMTTDTSTSTVYMELRSLRSDDTAVYYCARDYFYGMDVWGQGTTVTVSS (SEQ ID NO: 248) VHQVQLVQSGAEVKKPGSSVKVSCKTSGDTFSTYAISWVRQAPGQGLEWMGGIIPIFGKAHYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYFCARKFHFVSGSPFGMDVWGQGTTVTVSS (SEQ ID NO: 249) VHQVQLVQSGAEVKKPGASVKVSCKASGYTFTSYDVHWVRQAPGQRLEWMGWLHADTGITKFSQKFQGRVTITRDTSASTAYMELSSLRSEDTAVYYCARERIQLWFDYWGQGT (SEQ ID NO: 250) VHQVQLVQSGAEVKKPGSSVKVSCKVSGGIFSTYAINWVRQAPGQGLEWMGGIIPIFGTANHAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARDQGIAAALFDYWGQGTLVTVSS (SEQ ID NO: 251) VHEVQLVESGGGLVQPGRSLRLSCAVSGFTFDDYVVHWVRQAPGKGLEWVSGNSGNIGYADSVKGRFTISRDNAKNSLYLQMNSLRAEDTALYYCAVPFDYWGQGTLVTVSS (SEQ ID NO: 252) VHQVQLVQSGAEVKKPGSSVKVSCKTSGDTFSSYAISWVRQAPGQGLEWMGGIIPIFGRAHYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYFCARKFHFVSGSPFGMDVWGQGTTVTVSS (SEQ ID NO: 253) VHQVQLVQSGAEVKKPGSSVKVSCKTSGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGKAHYAQKFQGRVTITADESTTTAYMELSSLRSEDTAVYYCARKYDYVSGSPFGMDVWGQGTTVTVSS (SEQ ID NO: 254) VHQVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAINWVRQAPGQGLEWMGGIIPIFGSANYAQKFQDRVTITADESTSAAYMELSSLRSEDTAVYYCARDSSGWSRYYMDVWGQGTTVTVSS (SEQ ID NO: 255) VHQVQLVQSGAEVKEPGSSVKVSCKASGGTFNSYAISWVRQAPGQGLEWMGGIIPLFGIAHYAQKFQGRVTITADESTNTAYMDLSSLRSEDTAVYYCARKYSYSGSPFGMDVWGQGTTVTVSS (SEQ ID NO: 256) VHEVQLVESGGGLVQPGRSLRLSCARSGITFDDYGMHWVRQAPGKGLEWVSGISWNRGRIEYADSVKGRFTISRDNAKNSLYLQMNSLRAEDTALYYCAKGRFRYFDWFLDYWGQGTLVTVSS (SEQ ID NO: 257) VHQMQLVQSGGGLVQPGGSLRLSCAASGFTFSSYWMSWVRQAPGKGLEWVANIKQDGSEKYYVDSVKGRFTISRDNAKNSLYLQMNSLRAEDTAVYYCARDYFWSGESAFDIWGKGTLVTVS (SEQ ID NO: 449) VLEIVLTQSPATLSLSPGERATLSCRASQSVSSYLVWYQQKPGQAPRLLIYDASNRATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSNWPRTFGQGTKVEIK (SEQ ID NO: 258) VLEIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASNRATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSNWPTFGQGTKVEIK (SEQ ID NO: 259) VLDIQMTQSDSSLSASVGDRVTITCRASQGISSWLAWYQQKPEKAPKSLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYNSYPYTFGQGTKLEIK (SEQ ID NO: 260) VLEIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQYGSSPWTFGQGTKVEIK (SEQ ID NO: 261) VLEIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQYGSSPFGGGTKVEIK (SEQ ID NO: 262) VLEIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASNRATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSNWPTFGQGTRLEIK (SEQ ID NO: 263) VLAIQLTQSESSLSASVGDRVTITCRASQGISSALAWYQQKPGKAPKLLIYDASSLESGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQFNSYPFTFGPGTKVDIK (SEQ ID NO: 264)DIVMTQSPSTLSASVGDRVTITCRASQGISSWLAWYQQKPGRAPKVLIYKASTLESGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYSTPWTFGQGTKLEIK (SEQ ID NO: 450) Group B VHEVQLVESGGGLVQPGGSLRLSCAASGFTFSRYWMSWVRQAPGKGLEWVANIKQDGSEKYYVDSVKGRFTISRDNAKNSLYLQMNSLRAEDTAVYYCAREGGWFGELAFDYWGQGTLVTVSS (SEQ ID NO: 265) VLEIVLTQSPGTLSLSDGERATLSCRASQRVSSSYLAWYQQKPGQAPRLLIYDASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQYGSLPWTFGQGTKVEIK (SEQ ID NO: 266) Group C VHEVQLVESGGGLVQPGGSLRLSCAASGFTFSDSWIHWVRQAPGKGLEWVAWISPYGGSTYYADSVKGRFTISADTSKNTAYLQMNSLRAEDTAVYYCARRHWPGGFDYWGQGTLVTVSA (SEQ ID NO: 267) VHEVQLVESGGGLVQPGGSLRLSCAASGFTFSGSWIHWVRQAPGKGLEWVAWILPYGGSSYYADSVKGRFTISADTSKNTAYLQMNSLRAEDTAVYYCARRHWPGGFDYWGQGTLVTVSA (SEQ ID NO: 451) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYLYHPATFGQGTKVEIKR (SEQ ID NO: 268) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYYNVPWTFGQGTKVEIKR (SEQ ID NO: 452) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYYAPPWTFGQGTKVEIKR (SEQ ID NO: 453) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYYTVPWTFGQGTKVEIKR (SEQ ID NO: 454) VLDIQMTQSPSSLSASVGDRVTITCRASQVINTFLAWYQQKPGKAPKLLIYSASTLASGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYYTVPRTFGQGTKVEIKR (SEQ ID NO: 455) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQGYGVPRTFGQGTKVEIKR (SEQ ID NO: 456) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYLFTPPTFGQGTKVEIKR (SEQ ID NO: 457) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYFITPTTFGQGTKVEIKR (SEQ ID NO: 458) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYYYTPPTFGQGTKVEIKR (SEQ ID NO: 459) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQFFYTPPTFGQGTKVEIKR (SEQ ID NO: 460) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSLFTPPTFGQGTKVEIKR (SEQ ID NO: 461) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSLYTPPTFGQGTKVEIKR (SEQ ID NO: 462) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSWYHPPTFGQGTKVEIKR (SEQ ID NO: 463) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSRSFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYFYIPPTFGQGTKVEIKR (SEQ ID NO: 464) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYWYTPTTFGQGTKVEIKR (SEQ ID NO: 465) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYFIPPTFGQGTKVEIKR (SEQ ID NO: 466) Group D VHMETGLRWLLLVAVLKGVQCLSVEESGGRLVTPGTPLTLTCTASGFTITNYHMFWVRQAPGKGLEWIGVITSSGIGSSSTTYYATWAKGRFTISKTSTTVNLRITSPTTEDTATYFCARDYFTNTYYALDIWGPGTLVTVSS(SEQ ID NO: 467) VHQVQLVQSGAEVKKPGSSVKVSCKTSGDTFSTYAISWVRQAPGQGLEWMGGIIPIFGKAHYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVFCARKFHFVSGSPFGMDVWGQGTTVTVSS (SEQ ID NO: 249) VHQVQLVQSGAEVKKPGASVKVSCKASGYTFTSYDVHWVRQAPGQRLEWMGWLHADTGITKFSQKFQGRVTITRDTSASTAYMELSSLRSEDTAVYYCARERIQLWFDYWGQGTLVTVSS (SEQ ID NO: 468) VHQVQLVQSGAEVKKPGSSVKVSCKVSGGIFSTYAINWVRQAPGQGLEWMGGIIPIFGTANHAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARDQGIAAALFDYWGQGTLVTVSS (SEQ ID NO: 251) VHEVQLVESGGGLVQPGRSLRLSCAVSGFTFDDYVVHWVRQAPGKGLEWVSGISGNSGNIGYADSVKGRFTISRDNAKNSLYLQMNSLRAEDTALYYCAVPFDYWGQGTLVTVSS (SEQ ID NO: 469) VHQVQLVQSGAEVKKPGSSVKVSCKTSGDTFSSYAISWVRQAPGQGLEWMGGIIPIFGRAHYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYFCARKFHFVSGSPFGMDVWGQGTTVTVSS (SEQ ID NO: 253) VHQVQLVQSGAEVKKPGSSVKVSCKTSGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGKAHYAQKFQGRVTITADESTTTAYMELSSLRSEDTAVYYCARKYDYVSGSPFGMDVWGQGTTVTVSS (SEQ ID NO: 254) VHQVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAINWVRQAPGQGLEWMGGIIPIFGSANYAQKFQDRVTITADESTSAAYMELSSLRSEDTAVYYCARDSSGWSRYYMDVWGQGTTVTVSS (SEQ ID NO: 255) VHQVQLVQSGAEVKEPGSSVKVSCKASGGTFNSYAISWVRQAPGQGLEWMGGIIPLFGIAHYAQKFQGRVTITADESTNTAYMDLSSLRSEDTAVYYCARKYSYVSGSPFGMDVWGQGTTVTVSS (SEQ ID NO: 256) VHEVQLVESGGGLVQPGRSLRLSCAASGITFDDYGMHWVRQAPGKGLEWVSGISWNRGRIEYADSVKGRFTISRDNAKNSLYLQMNSLRAEDTALYYCAKGRFRYFDWFLDYWGQGTLVTVSS (SEQ ID NO: 257) VLMDTRAPTQLLGLLLLWLPGARCALVMTQTPSSTSTAVGGTVTIKCQASQSISVYLAWYQQKPGQPPKLLIYSASTLASGVPSRFKGSRSGTEYTLTISGVQREDAATYYCLGSAGS (SEQ ID NO: 470) VLEIVLTQSPATLSLSPGERATLSCRASQSVSSYLVWYQQKPGQAPRLLIYDASNRATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSNWPRTFGQGTKVEIK (SEQ ID NO: 258) VLEIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASNRATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSNWPTFGQGTKVEIK (SEQ ID NO: 259) VLDIQMTQSPSSLSASVGDRVTITCRASQGISSWLAWYQQKPEKAPKSLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYNSYPYTFGQGTKLEIK (SEQ ID NO: 260) VLEIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQYGSSPWTFGQGTKVEIK (SEQ ID NO: 261) VLEIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQYGSSPFGGGTKVEIK (SEQ ID NO: 262) VLEIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASNRATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQRSNWPTFGQGTRLEIK (SEQ ID NO: 263) VLAIQLTQSPSSLSASVGDRVTITCRASQGISSALAWYQQKPGKAPKLLIYDASSLESGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQFNSYPFTFGPGTKVDIK (SEQ ID NO: 264) Group E VHEVQLLESGGGLVQPGGSLRLSCAASGFTFSSYIMMWVRQAPGKGLEWVSSIYPSGGITFYADTVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARIKLGTVTTVDYWGQGTLVTVSS (SEQ ID NO: 471) VLQSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSNRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSSSTRVFGTGTKVTVL (SEQ ID NO: 472) Group F VHEVKLQESGPSLVKPSQTLSLTCSVTGYSITSDYWNWIRKFPGNKLEYVGYISYTGSTYYNPSLKSRISITRDTSKNQYYLQLNSVTSEDTATYYCARYGGWLSPFDYWGQGTTLTVSS (SEQ ID NO: 473) VHEVQLQESGPGLVAPSQSLSITCTVSGFSLTTYSINWIRQPPGKGLEWLGVMWAGGGTNSNSVLKSRLIISKDNSKSQVFLKMNSLQTDDTARYYCARYYGNSPYYAIDYWGQGTSVTVSS (SEQ ID NO: 474) VHEVKLQESGPSLVKPSQTLSLTCSVTGYSIISDYWNWIRKFPGNKLEYLGYISYTGSTYYKPSLKSRISITRDTSKNQYYLQLNSVTTEDTATYYCARRGGWLLPFDYWGQGTTLTVSS (SEQ ID NO: 475) VHEVKLQESGPSLVKPGASVKLSCKASGYTFTSYDINWVKQRPGQGLEWIGWIFPRDNNTKYKENFKGKATLTVDTSSTTAYMELHSLTSEDSAVYFCTKENWVGDFDYWGQGTTLTLSS (SEQ ID NO: 476) VHEVQLQQSGPDLVTPGASVRISCQASGYTFPDYYMNWVKQSHGKSLEWIGDIDPNYGGTTYNQKFKGKAILTVDRSSSTAYMELRSLTSEDSAVYYCARGALTDWGQGTSLTVSS (SEQ ID NO: 477) VHEIVLTQSPATLSLSPGERATLSCRASSSVSYIYWFQQKPGQSPRPLIYAAFNRATGIPARFSGSGSGTDYTLTISSLEPEDFAVYYCQQWSNNPLTFGQGTKVEIK (SEQ ID NO: 478) VHQVQLVQSGAEVKKPGASVKVSCKASGYTFPDYYMNWVRQAPGQGLEWMGDIDPNYGGTNYAQKFQGRVTMTRDTSISTAYMELSRLRSDDTAVYYCARGALTDWGQGTMVTVSS (SEQ ID NO: 479) VHQVQLVQSGAEVKKPGASVKVSCKASGYTFPDYYMNWVRQAPGQSLEWMGDIDPNYGGTNYNQKFQGRVTMTRDTSISTAYMELSRLRSDDTAVYYCARGALTDWGQGTMVTVSS (SEQ ID NO: 480) VHEVQLVQSGAEVKKPGASVKVSCKASGYTFPDYYMNWVRQAPGQSLEWMGDIDPNYGGTNYNQKFQGRVTMTVDRSSSTAYMELSRLRSDDTAVYYCARGALTDWGQGTMVTVSS (SEQ ID NO: 481) VHEVQLVESGGGLVQPGRSLRLSCTASGYTFPDYYMNWVRQAPGKGLEWVGDIDPNYGGTTYAASVKGRFTISVDRSKSIAYLQMSSLKTEDTAVYYCTRGALTDWGQGTMVTVSS (SEQ ID NO: 482) VHEVQLVESGGGLVQPGRSLRLSCTASGYTFPDYYMNWVRQAPGKGLEWVGDIDPNYGGTTYNASVKGRFTISVDRSKSIAYLQMSSLKTEDTAVYYCARGALTDWGQGTMVTVSS (SEQ ID NO: 483) VLDIVMTQSHKLMSTSVGDRVSITCKASQDVGTAVAWYQQKPGQSPKLLIYWASTRHTGVPDRFTGSGSGTDFTLTISNVQSEDLADYFCQQDSSYPLTFGAGTKVELK (SEQ ID NO: 484) VLDIVTTQSHKLMSTSVGDRVSITCKASQDVGTAVAWYQQKPGQSPKLLIYWASTRHTGVPDRFTGSGSGTDFTLTISNVQSEDLADYFCQQDSSYPLTFGAGTKVELK (SEQ ID NO: 485) VLDIVMTQSPSSLAVSVGEKVSMGCKSSQSLLYSSNQKNSLAWYQQKPGQSPKLLIDWASTRESGVPDRFTGSGSGTDFTLTISSVKAEDLAVYYCQQYYGYPLTFGAGTKLELK (SEQ ID NO: 486) VLDIVMTQSPAIMSASPGEKVTMTCSASSSIRYMHWYQQKPGTSPKRWISDTSKLTSGVPARFSGSGSGTSYALTISSMEAEDAATYYCHQRSSYPWTFGGGTKLEIK (SEQ ID NO: 487) VLQIVLSQSPAILSASPGEKVTMTCRASSSVSYIYWFQQKPGSSPKPWIYATFNLASGVPARFSGSGSGTSYSLTISRVETEDAATYYCQQWSNNPLTFGAGTKLELK (SEQ ID NO: 488) VLEIVLTQSPATLSLSPGERATLSCRASSSVSYIYWFQQKPGQAPRLLIYAAFNRATGIPARFSGSGSGTDYTLTISSLEPEDFAVYYCQQWSNNPLTFGQGTKVEIK (SEQ ID NO: 489) VLQIVLTQSPATLSLSPGERATLSCRASSSVSYIYWFQQKPGQSPRPLIYATFNLASGIPARFSGSGSGTSYTLTISRLEPSDFAVYYCQQWSNNPLTFGQGTKVEIK (SEQ ID NO: 490) VLDIQLTQSPSSLSASVGDRVTITCRASSGVSYIYWFQQKPGKAPKLLIYAAFNLASGVPSRFSGSGSGTEYTLTISSLQPSDFATYYCQQWSNNPLTFGQGTKVEIK (SEQ ID NO: 491) VLDIQLTQSPSSLSASVGDRVTITCRASSGVSYIYWFQQKPGKAPKPLIYAAFNLASGVPSRFSGSGSGTEYTLTISSLQPEDFATYYCQQWSNNPLTFGQGTKVEIK (SEQ ID NO: 492) VLDIQLTQSPSILSASVGDRVTITCRASSSVSYIYWFQQKPGKAPKPLIYATFNLASGVPSRFSGSGSGTSYTLTISSLQPEDFATYYCQQWSNNPLTFGQGTKVEIK (SEQ ID NO: 493) Group G VHQVQLVQSGAEVKKPGASVKVSCKASGYTFTSYGISWVRQAPGQGLEWMGWISAYNGNTNYAQKLQGRVTMTTDTSTSTAYMELRSLRSDDTAVYYCARALPSGTILVGGWFDPWGQGTLVTVSS (SEQ ID NO: 494) VHQVQLVQSGGGVVQPGRSLRLSCAASGFTFSSYALSWVRQAPGKGLEWVSAISGGGGSTYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKDVFPETFSMNYGMDVWGQGTLVTVSS (SEQ ID NO: 495) VHQVQLVQSGGGVVQPGGSLRLSCAASGFTFDDYAMHWVRQAPGKGLEWVSLISGDGGSTYYADSVKGRFTISRDNSKNSLYLQMNSLRTEDTALYYCAKVLLPCSSTSCYGSVGAFDIWGQGTTVTVSS (SEQ IDNO: 496) VHQVQLVQSGGSVVRPGESLRLSCVASGFIFDNYDMSWVRQVPGKGLEWVSRVNWNGGSTTYADAVKGRFTISRDNTKNSLYLQMNNLRAEDTAVYYCVREFVGAYDLWGQGTTVTVSS (SEQ ID NO: 497) VHQVQLVQSGAEVKKPGATVKVSCKVFGDTFRGLYIHWVRQAPGQGLEWMGGIIPIFGTANYAQKFQGRVTITTDESTSTAYMELSSLRSEDTAVYYCASGLRWGIWGWFDPWGQGTLVTVSS (SEQ ID NO: 498) VHEVQLVQSGAELKKPGSSVKVSCKAFGGTFSDNAISWVRQAPGQGPEWMGGIIPIFGKPNYAQKFQGRVTITADESTSTAYMVLSSLRSEDTAVYYCARTMVRGFLGVMDVWGQGTTVTVSS (SEQ ID NO: 499) VHQVQLVQSGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSAISGSGGSTYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKDQFVTIFGVPRYGMDWGQGTTVTVSS (SEQ ID NO: 500) VHQVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGTANYAQKFQGRVTITADKSTSTAYMELSSLRSEDTAVYYCARGRQMFGAGIDFWGPGTLVTVSS (SEQ ID NO: 501) VHEVQLVESGAEVKKPGSSVKVSCKVSGGTFGTYALNWVRQAPGQGLEWMGRIVPLIGLVNYAHNFEGRISITADKSTGTAYMELSNLRSDDTAVYYCAREVYGGNSDYWGQGTLVTVSS (SEQ ID NO: 502) VHQVQLVQSGGEVKKPGASVKVSCKASGYTLSSHGITWVRQAPGQGLEWMGWISAHNGHASNAQKVEDRVTMTTDTSTNTAYMELRSLTADDTAVYYCARVHAALYYGMDVWGQGTLVTVSS (SEQ ID NO: 503) VHQVQLQESGGGVVQPGRSLRLSCSASGFTFSRHGMHWVRQAPGKGLEWVAVISHDGSVKYYADSMKGRFSISRDNSNNTLYLQMDSLRADDTAVYYCARGLSYQVSGWFDPWGQGTLVTVSS (SEQ ID NO: 504) VHNFMLTQPHSVSESPGKTVTISCTRSSGSIASNYVQWYQQRPGSSPTTVIYEDNQRPSGVPDRFSGSIDTSSNSASLTISGLKTKDEADYYCQSYDGITVIFGGGTKLTVL (SEQ ID NO: 505) VHNFMLTQPHSVSGSPGKTVTLPCTRSSGSIASHYVQWYQQRPGSAPTTVIYEDNKRPSGVPDRFSGSIDSSSNSASLSISGLKTEDEADYYCQSYDSSNRWVFGGGTKLTVL (SEQ ID NO: 506) VHLPVLTQPASLSASPGASASLTCTLRSGLNVGSYRIYWYQQKPGSRPQYLLNYKSDSNKQQASGVPSRFSGSKDASANAGILLISGLQSEDEADYYCMIWYSSAVVFGGGTKLTVL (SEQ ID NO: 507) VLNFMLTQPHSVSESPGKTVTISCTRSSGNIASNYVQWYQQRPGSAPTTVIYEDNQRPSGVPDRFSGSIDSSSNSASLTISGLKTEDEADYYCQSYDSSNLWVFGGGTKLTVL (SEQ ID NO: 508)    VLSSELTQDPAVSVALGQTVRITCQGDSLRSYYASWYQQKPGQAPVLVIYGKNNRPSGIPDRFSGSSSGNTASLTITGAQAEDEADYYCNSRDSSGNHYVFGTGTKVTVL (SEQ ID NO: 509) VLLPVLTQAPSVSVAPGKTARITCGGSDIGRKSVHWYQQKPGQAPALVIYSDRDRPSGISERFSGSNSGNTATLTISRVEAGDEADYYCQVWDNNSDHYVFGAGTELIVL (SEQ ID NO: 510) VLQSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSNRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSSTLPFGGGTKLTVL (SEQ ID NO: 511) VLEIVLTQSPATLSLSPGERATLSCRASQSIGNSLAWYQQKPGQAPRLLMYGASSRATGIPDRFSGSGAGTDFTLTISSLEPEDFATYYCQQHTIPTFSFGPGTKVEVK (SEQ ID NO: 512) VLDIVMTQTPSFLSASIGDRVTITCRASQGIGSYLAWYQQRPGEAPKLLIYAASTLQSGVPSRFSGSGSGTDFTLTISNLQPEDFATYYCQQLNNYPITFGQGTRLEIK (SEQ ID NO: 513) VLQSALTQPPSVSVSPGQTANIPCSGDKLGNKYAYWYQQKPGQSPVLLIYQDIKRPSRIPERFSGSNSADTATLTISGTQAMDEADYYCQTWDNSVVFGGGTKLTVL (SEQ ID NO: 514) VLNFMLTQPHSVSESPGKTVTISCTRSSGSIDSNYVQWYQQRPGSAPTTVIYEDNQRPSGVPDRFSGSIDSSSNSASLTISGLKTEDEADYYCQSYDSNNRHVIFGGGTKLTVL (SEQ ID NO: 515) VLNFMLTQPHSVSESPGKTVTISCTRSSGNIGTNYVQWYQQRPGSAPVALIYEDYRRPSGVPDRFSGSIDSSSNSASLIISGLKPEDEADYYCQSYHSSGWEFGGGTKLTVL (SEQ ID NO: 516) VLQSVLTQPPSVSVAPGQTARITCGGNNIGSKGVHWYQQKPGQAPVLVVYDDSDRPSGIPERFSGSNSGNTATLTISRVEAGDERDYYCQVWDSSSDHWVFGGGTKLTVL (SEQ ID NO: 517) VLNFMLTQPHSVSESPGKTVTISCTRSSGSIASNYVQWYQQRPGSAPTTVIYEDNQRPSGVPDRFSGSIDSSSNSASLTISGLKTEDEADYYCQSYDSTTPSVFGGGTKLTVL (SEQ ID NO: 518) VLQVQLVQSGAEVKKPGASVKVSCKASGYTFTSYGISWVRQAPGQGLEWMGWTSPHNGLTAFAQILEGRVTMTTDTSTNTAYMELRNLTFDDTAVYFCAKVHPVFSYALDVWGQGTLVTVSS (SEQ ID NO: 519) VLEVQLVESGAEVMNPGSSVRVSCRGSGGDFSTYAFSWVRQAPGQGLEWMGRIIPILGIANYAQKFQGRVTITADKSTSTAYMELSSLRSDDTAVYYCARDGYGSDPVLWGQGTLVTVSS (SEQ ID NO: 520) VLEVQLVQSGAEVKKPGASVKVSCKASGYTFTNYGISWVRQAPGQGLEWMGWISAYNGNTNYAQKVQGRVTMTTDTSTSTGYMELRSLRSDDTAVYYCARGDFRKPFDYWGQGTLVTVSS (SEQ ID NO: 521) Group HVHEVQLVQSGPELKKPGASVKMSCKASGYTFTSYVMHWVKQAPGQRLEWIGYVNPFNDGTKYNEMFKGRATLTSDKSTSTAYMELSSLRSEDSAVYYCARQAWGYPWGQGTLVTVSS (SEQ ID NO: 522) VHEVQLVQSGAEVKKPGASVKMSCKASGYTFTSYVMHWVKQAPGQRLEWIGYVNPFNDGTKYNEMFKGRATLTSDKSTSTAYMELSSLRSEDTAVYYCARQAWGYPWGQGTLVTVSS (SEQ ID NO: 523) VHEVQLVQSGAEVKKPGASVKMSCKASGYTFTSYVMHWVRQAPGQRLEWIGYVNPFNDGTKYNEMFKGRATLTSDKSTSTAYMELSSLRSEDTAVYYCARQAWGYPWGQGTLVTVSS (SEQ ID NO: 524) VHEVQLVQSGAEVKKPGASVKVSCKASGYTFTSYVMHWVRQAPGQRLEWIGYVNPFNDGTKYNEMFKGRATLTSDKSTSTAYMELSSLRSEDTAVYYCARQAWGYPWGQGTLVTVSS (SEQ ID NO: 525) VHEVQLVQSGAEVKKPGASVKVSCKASGYTFTSYVMHWVRQAPGQRLEWIGYVNPFNDGTKYNEMFKGRATITSDKSTSTAYMELSSLRSEDTAVTYCARQAWGYPWGQGTLVTVSS (SEQ ID NO: 526) VLDIVLTQSPASLALSPGERATLSCRATESVEYYGTSLVQWYQQKPGQPPKLLIYAASSVDSGVPSRFSGSGSGTDFTLTINSLEEEDAAMYFCQQSRRVPYTFGQGTKLEIK (SEQ ID NO: 527) VLDIVLTQSPATLSLSPGERATLSCRATESVEYYGTSLVQWYQQKPGQPPKLLIYAASSVDSGVPSRFSGSGSGTDFTLTINSLEAEDAAMYFCQQSRRVPYTFGQGTKLEIK (SEQ ID NO: 528) VLEIVLTQSPATLSLSPGERATLSCRATESVEYYGTSLVQWYQQKPGQPPKLLIYAASSVDSGVPSRFSGSGSGTDFTLTINSLEAEDAAMYFCQQSRRVPYTFGQGTKLEIK (SEQ ID NO: 529) VLDIVLTQSPATLSLSPGERATLSCRATESVEYYGTSLVQWYQQKPGQPPKLLIYAASSVDSGVPSRFSGSGSGTDFTLTINSLEAEDAATYFCQQSRRVPYTFGQGTKLEIK (SEQ ID NO: 530) Group I VHEVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGTANYAQKFQGRVTITADKSTSTAYMELSSLRSEDTAVYYCAREGTIYDSSGYSFDYWGQGTLVTVSS (SEQ ID NO: 531) VHEVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGIIKPSGGSTSYAQKFQGRVSMTRDTSTSTVYMELSSLTSEDTAVYYCARDLFPHIYGNYYGMDIWGQGTTVTVSS (SEQ ID NO: 532) VHQVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGTANYAQKFQGRVTITADKSTSTAYMELSSLRSEDTAVYYCARLAVPGAFDIWGQGTMVTVSS (SEQ ID NO: 533) VHEVQLVESGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLAVISYDGSNKYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGQWLVTELDYWGQGTLVTVSS (SEQ ID NO: 534) VHEVQLVESGSEVEKPGSSVKVSCKASGGTFSDSGISWVRQAPGQGLEWMGGIIPMFATPYYAQKFQDRVTITADESTSTVYMELSGLRSDDTAVFYCARDRGRGHLPWYFDLWGRGTLVTVSS (SEQ ID NO: 535) VHEVQLVESGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGTANYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARAPYYYYYMDVWGQGTTVTVSS (SEQ ID NO: 536) VHEVQLLESGAEVKKPGSSVKVSCKASGGTLSRYALSWVRQAPGQGPEWVGAIIPIFGTPHYSKKFQDRVTITVDTSTNTAFMELSSLRFEDTALYFCARGHDEYDISGYHRLDYWGQGTLVTVSS (SEQ ID NO: 537) VHQVQLVQSGSELKKPGSSVKVSCKASGYSFSGYYIHWVRQAPGQGLEVWMGWIDPNSGVTNYVRRFQGRVTMTRDTSLSTAYMELSGLTADDTAVYYCARDENLWQFGYLDYWGQGTLVTVSS (SEQ ID NO: 538) VHQVQLVQSGAEVKKPGSSVKVSCKASGGTFSRYGVHWVRQAPGQGLEWMGRLIPIVSMTNYAQKFQDRVSITTDKSTGTAYMELRSLTSEDTALYYCASVGQQLPWVFFAWGQGTLVTVSS (SEQ ID NO: 539) VHQVQLVESGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 540) VHEVQLVESGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 541) VHEVQLVQSGGGLVQPGGSLRLSCAASGFTFSDYGMHWVRQPPGKGLEWLAVISYDGSYKIHADSVQGRFTISRDNAKNSVFLQMNSLKTEDTAVYYCTTDRKWLAWHGMDVWGQGTTVTVSS (SEQ ID NO: 542) VHEVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGTANYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARDGIVADFQHWGQGTLVTVSS (SEQ ID NO: 543) VHEVQLVESGAEVKKPGASVKVSCKASGDTFSRYGITWVRQAPGRGLEWMGNIVPFFGATNYAQKFQGRLTITADKSSYTSYMDLSSLRSDDTAVYYCARDHFYGSGGYFDYWGQGTLVTVSS (SEQ ID NO: 544) VHEVQLLESGAEVKKPGASVKVSCKASGYTFNSYDINWVRQAPGQGLEWMGGIIPVFGTANYAESFQGRVTMTADHSTSTAYMELNNLRSEDTAVYYCARDRWHYESRPMDVWGQGTTVTVSS (SEQ ID NO: 545) VHEVQLVESGGGLVRPGGSLRLACAASGFSFSDYYMTWIRQAPGRGLEWIAYISDSGQTVHYADSVKGRFTISRDNTKNSLFLQVNTLRAEDTAVYYCAREDLLGYYLQSWGQGTLVTVSS (SEQ ID NO: 546) VHQVQLQQSGPGLVKPSQTLSLTCAISGDSVSSNSAAWNWIRQSPSRGLEWLGRTYYRSKWYNDYAVSVKSRITINPDTSKNQFSLQLNSVTPEDTAVYYCARDEPRAVAGSQAYYYYGMDWGQGTTVTVSS (SEQ IDNO: 547) VHEVQLVQSGAEVKKPGASVKVSCKASGYTFTSYYMHWVRQAPGQGLEWMGIINPSDGSTSYAQKFQGRVTMTRDTSTSTVHMELSSLRSEDTAVYYCARDLFPHIYGNYYGMDIWGQGTTVTVSS (SEQ ID NO: 548) VHQMQLVQSGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 549) VHQVQLVQSGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 550) VLQSVLTQPPSVSAAPGQKVTISCSGNNSNIANNYVSWYQQLPGTAPKLLIYDNNYRPSGIPDRFSGSKSGTSATLDITGLQTGDEADYYCGVWDGSLTTGVFGGGTKLTVL (SEQ ID NO: 551) VLAIQMTQSPSSLSASVGDRVTITCRASQGISNYLAWYQQKPGKVPKLLIYAASTLESGVPSRFSGSGSGTDFTLTISSLQPEDLATYYCQQLHTFPLTFGGGTKVEIK (SEQ ID NO: 552) VLQPVLTQPPSASGSPGQSVTISCTGTSSDVGAYNFVSWYRQHPGKAPKLMIYEVNKRPSGVPDRFSGSKSGNTASLTVSGLQAEDEADYYCSSYAGTNSLGIFGTGTKLTVL (SEQ ID NO: 553) VLQSVVTQPPSVSAAPGQKVTISCSGSSSDIGNHYVSWYQQLPGTAPKLLIYDNNQRPSGIPDRFSGSKSGTSATLAITGLQTGDEADYYCGTWDNSLSPHLLFGGGTKLTVL (SEQ ID NO: 554) VLQSVLTQPPSVSAAPGQKVTISCSGSSSNMGNNYVSWYKQVPGTAPKLLIYENDKRPSGIPDRFSGSKSGTSATLGITGLQTGDEADYYCGTWDNSLSGFVFASGTKVTVL (SEQ ID NO: 555) VLQSALTQPASVSGSLGQSVTISCTGSSSDVGSYNLVSWYQQHPGKAPNLMIYDVSKRSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTGISTVVFGGGTKLTVL (SEQ ID NO: 556) VLQSVLTQPASVSGSPGQSITISCTGTSSDVGSYNLVSWYQQHPGKAPKLMIYEVSKRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYGGFNNLLFGGGTKLTVL (SEQ ID NO: 557) VLDIVMTQSPSSLSASIGDRVTITCRASQRISAYVNWYQQKPGKAPKVLIYAASSLRSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQTYSSPWTFGQGTKVEIK (SEQ ID NO: 558) VLQSVLTQPPSASGSPGQSVTISCTGTSSDIGGYDSVSWYQQHPGKAPKLMIYDVSKRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSSSIFFYVFGTGTKVTVL (SEQ ID NO: 559) VLLPVLTQPASVSGSPGQSITISCTGTTSDIGGYDYVSWYQQHPGKAPKLMIYDVSKRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSSSTHVFGTGTKLTVL (SEQ ID NO: 560) VLQSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSNRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYRSSTLGPVFGGGTKLTVL (SEQ ID NO: 561) VLQAGLTQPPSVSEAPRQRVTISCSGSSSNIGNNAVNWYQQLPGKAPKLLIYYDDLLPSGVSDRFSGSKSGTSASLAISGLQSEDEADYYCAAWDDSLNGYVFGTGTKLTVL (SEQ ID NO: 562) VLQSALTQPRSVSGSPGQSVTISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSKRPSGVPDRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSSTTHVFGTGTKVTVL (SEQ ID NO: 563) VLQSVVTQPPSVSAAPGQKVTISCSGSSSNIGNNYVSWYQQLPGTAPKLLIYDNNKRPSGIPDRFSGSKSGTSATLGITGLQTGDEADYYCGTWDSSLSVWVFGGGTQLTVL (SEQ ID NO: 564) VLQSVLTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGRAPRLMIYDVSNRPSGVSNRFSGSKSGNTASLTISGLQAEDEGDYYCSSYTSGGTLGPVFGGGTKLTVL (SEQ ID NO: 565) VLQAGLTQPPSASGTPGQRVTISCSGSSSNIGSNTVNWYQQLPGTAPKLLIYSNNQRPSGVPDRFSGSKSGTSASLAISGLQSEDEADYYCAAWDDSLNGWFGGGTKLTVL (SEQ ID NO: 566) VLAIRMTQSPSSLSASVGDRVTITCRASQSISNYLNWYQQRPGKAPNLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQTYSTPYTFGQGTKLEIK (SEQ ID NO: 567) VLQSVLTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYRQHPGKAPKLMIYDVSYRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTDSSTRYVFGTGTKLTVL (SEQ ID NO: 568) VLQPVLTQPPSASGTPGQRVAISCSGSRSKIEINSVNWYQQLPGTAPKLLIYDKNKRPSGIPDRFSGSKSGTSATLGITGLQTGDEADYYCGSWDSSLSADVFGTGTKLTVL (SEQ ID NO: 569) VLQSVLTQPPSVSAAPGKKVTISCSGSSSNIGNNYVSWYQQLPGTAPKLLIYRNNQRPSGVPDRFSGSKSGTSASLAISGLQSEDEADYYCATWDDSLNGWVFGGGTKLTVL (SEQ ID NO: 570) VLQSVVTQPPSVSGAPGQRVTISCTGSSSNIGAGYDVHWYQQLPGTAPKLLIYGNNNRHSGVPDRFSGSKSGTSASLAITGLQAEDEAEFFCGTWDSRLTTYVFGSGTKLTVL (SEQ ID NO: 571) VLQSVVTQPPSVSAAPGQKVTISCSGSSSNIGNNYVSWYQQLPGTAPKLLIYDNNKRPSGIPDRFSGSKSGTSATLGITGLQTGDEADYYCGTWDSSLSAVVFGGGTKLTVL (SEQ ID NO: 572) VLVIWMTQSPSSLSASVGDRVTITCAASSLQSWYQQKPGKAPKLLIYEASTLESGVPSRFSGSGSGTEFTLTISSLQPEDFATYYCQQSYSTPYTFGQGTKLEIK (SEQ ID NO: 573) VLQSVVTQPPSVSAAPGQKVTISCSGSSSNIGNNYVSWYQQVPGTAPKLLIYDNNKRPSGIPDRFSGSNSDTSATLGITGLQTGDEADYYCGTWDSSLSAWVFGGGTKLTVL (SEQ ID NO: 574) VLQSVVTQPPSVSAAPGQKVTISCSGSSSNIGNNYVSWYQQLPGTAPKLLIYDNNKRPSGIPDRFSGSKSGTSATLGITGLQTGDEADYYCGTWDSSLSAGSWFGGGTKLTVL (SEQ ID NO: 575) VLSYELMQPPSVSVAPGKTATIACGGENIGRKTVHWYQQKPGQAPVLVIYYDSDRPSGIPERFSGSNSGNTATLTISRVEAGDEADYYCLWDSSSDHRIFGGGTKLTVL (SEQ ID NO: 576) VLSYELMQPPSVSVAPGKTATIACGGENIGRKTVHWYQQKPGQAPVLVIYYDSDRPSGIPERFSGSNSGNTATLTISRVEAGDEADYYCQWDSSSDHRIFGGGTKLTVL (SEQ ID NO: 577) VLSYELMQPPSVSVAPGKTATIACGGENIGRKTVHWYQQKPGQAPVLVIYYDSDRPSGIPERFSGSNSGNTATLTISRVEAGDEADYYCQVWDSSSDHRIFGGGTKLTVL (SEQ ID NO: 578) VLSYELMQPPSVSVAPGKTATIACGGENIGRKTVHWYQQKPGQAPVLVIYYDSDRPSGIPERFSGSNSGNTATLTISRVEAGDEADYYCQVWDSSSDHRIFGGGTKLTVL (SEQ ID NO: 579) Group J* HCQVQLVQSGVEVKKPGASVKVSCKASGYTFTNYYMYWVRQAPGQGLEWMGGINPSNGGTNFNEKFKNRVTLTTDSSTTTAYMELKSLQFDDTAVYYCARRDYRFDMGFDYWGQGTTVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGK (SEQ ID NO: 580) HCQVQLVESGGGVVQPGRSLRLDCKASGITFSNSGMHWWVRQAPGKGLEWVAVIWYDGSKRYYADSVKGRFTISRDNSKNTLFLQMNSLRAEDTAVYYCATNDDYWGQGTLVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDKKPSNTKVDKRVESKYGPPCPPCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGK (SEQ ID NO: 581) LCEIVLTQSPATLSLSPGERATLSCRASKGVSTSGYSYLHWYQQKPGQAPRLLIYLASYLESGVPARFSGSGSGTDFTLTISSLEPEDFAVYYCQHSRDLPLTFGGGTKYEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 582) LCEIVLTQSPATLSLSPGERATLSCRASQSVSSYLAWYQQKPGQAPRLLIYDASNRATGIPARFSGSGSGTDFTLTISSLEPEDFAVYYCQQSSNWPRTFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC(SEQ ID NO: 583) Group K VHEVQLVESGGGLVQPGGSLRLSCAASGFTFSDSWIHWVRQAPGKGLEWVAWISPYGGSTYYADSVKGRFTISADTSKNTAYLQMNSLRAEDTAVYYCARRHWPGGFDYWGQGTLVTVSSASTK (SEQ ID NO: 735) VHEVQLVESGGGLVQPGGSLRLSCAASGFTFSDSWIHWVRQAPGKGLEWVAWISPYGGSTYYADSVKGRFTISADTSKNTAYLQMNSLRAEDTAVYYCARRHWPGGFDYWGQGTLVTVSS (SEQ ID NO: 736) HCEVQLVESGGGLVQPGGSLRLSCAASGFTFSDSWIHWVRQAPGKGLEWVAWISPYGGSTYYADSVKGRFTISADTSKNTAYLQMNSLRAEDTAVYYCARRHWPGGFDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG (SEQ ID NO: 737) VLDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYLYHPATFGQGTKVEIKR (SEQ ID NO: 268) LCDIQMTQSPSSLSASVGDRVTITCRASQDVSTAVAWYQQKPGKAPKLLIYSASFLYSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYLYHPATFGQGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC(SEQ ID NO: 738) Group L VHEVQLVESGGGLVQPGGSLRLSCAASGFTFSRFWMSWVRQAPGKGLEWVANINQDGTEKYYVDSVKGRFTISRDNAKNSLYLQMNSLRAGDTAVYYCANTYYDFWSGHFDYWGQGTLVTVSS (SEQ ID NO: 739) VHQEHLVESGGGVVQPGRSLRLSCEASGFTFSNFGMHWVRQAPGKGLEWVAALWSDGSNKYYADSVKGRVTISRDNSKNTLYLQMNSLRAEDTAVYYCARGRGAPGIPIFGYWGQGTLVTVSS (SEQ ID NO: 740) VHEVQLVESGGGLVKPGGSLRLSCAASGFTFSNAWMSWVRQAPGKGLEWVGRIKRKTDGGTTDYAAPVKGRFTISRDDSKNTLHLQMNSLKTEDTAVYYCTTDDIVVVPAVMREYYFGMDVWGQGTTVTVSS (SEQ IDNO: 741) VHQVQLVQSGAEVKKPGASVQVSCKASGYSFTGYYIHWVRQAPGQGLEWMGWINPNSGTKKYAHKFQGRVTMTRDTSIDTAYMILSSLISDDTAVYYCARDEDWNFGSWFDSWGQGTLVTVSS (SEQ ID NO: 742) VHQVHLVQSGAEVKKPGASVKVSCKASGYTFTGYYIHWVRQAPGHGLEWMGWLNPNTGTTKYIQNFQGRVTMTRDTSSSTAYMELTRLRSDDTAVYYCARDEDWNYGSWFDTWGQGTLVTVSS (SEQ ID NO: 743) VHEVQLVESGGGVVRPGGSLRLSCAASGFTFDDYGMTWVRQAPGRGLEWVSGIHWHGKRTGYADSVKGRFTISRDNAKKSLYLQMNSLKGEDTALYHCVRGGMSTGDWFDPWGQGTLVIVSS (SEQ ID NO: 744) VHEVQLVESGGGVVRPGGSLRLSCAASGFTFDDYGMTWVRQVPGKGLEWVSGIHWSGRSTGYADSVKGRFTISRDNAKNSLYLQMNSLRAEDTALYYCARGGMSTGDWFDPWGQGTLVTVSS (SEQ ID NO: 745) VHEVQLVESGGGLVQPGGSLRLSCAASGFTVGSNYMNWVRQAPGKGLEWVSVIYSGGSTYYADSVKGRFTISRLTSKNTLYLQMSSLRPEDTAVYYCARGIRGLDVWGQGTTVTVSS (SEQ ID NO: 746) VHEERLVESGGDLVQPGGSLRLSCAASGITVGTNYMNWVKQAPGKGLEWVSVISSGGNTHYADSVKGRFIMSRQTSKNTLYLQMNSLETEDTAVYYCARGIRGLDVWGQGTMVTVSS (SEQ ID NO: 747) VHQVQLVQSGAEVKMPGSSVRVSCKASGGIFSSSTISWVRQAPGQGLEWMGEIIPVFGTVNYAQKFQDRVIFTADESTTTAYMELSSLKSGDTAVYFCARNWGLGSFYIWGQGTMVTVSS (SEQ ID NO: 748) VHEVQLVESGGDLVHPGRSLRLSCAASGFPFDEYAMHWVRQVPGKGLEWVSGISWSNNNIGYADSVKGRFTISRDNAKNSLYLQMNSLRPEDTAFYYCAKSGIFDSWGQGTLVTVSS (SEQ ID NO: 749) VHEVQLVESGGGVVQPGRSLRLSCAASGFTFSSYGMHWVRQAPGKGLEWVTLISYEGRNKYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKDRTLYGMDVWGQGTTVTVSS (SEQ ID NO: 750) VHQVTLRESGPALVKTTQTLTLTCTFSGFSLSTNRMCVTWIRQPPGKALEWLARIDWDGVKYYNTSLKTRLTISKDTSKNQVVLTMTNMDPVDTATFYCARSTSLTFYYFDYWGQGTLVTVSS (SEQ ID NO: 751) VHEVQLVESGGGLVQPGGSLRLSCAASEFTVGTNHMNWVRQAPGKGLEWVSVIYSGGNTFYADSVKGRFTISRHTSKNTLYLQMNSLTAEDTAVYYCARGLGGMDVWGQGTTVTVSS (SEQ ID NO: 752) VHEVQLVESGGGLVQRGESLRLYCAASGFTFSKYWMNWVRQAPGKGLEWVANIKGDGSEKYYVDSVKGRFTISRDNAKNSLYLQMNSLRAEDTAVYYCARDYWGSGYYFDFWGQGTLVTVSS (SEQ ID NO: 753) VHEVQLVESGGGLVQSGGSLRLSCAASGFTFSSYWMSWVRQAPGKGLEWVANIKQDGSEKYYVDSVKGRFTISRDNAKNSLYLQMNSLRADDTAVYYCARDDIVVVPAPMGYYYYYFGMDVWGQGTTVTVSS (SEQ IDNO: 754) VHEVQLVESGGGLVQPGRSLRLSCAASGFTFDDFAMHWVRQAPGKGLEWVSGISWTGGNMDYANSVKGRFTISREDAKNSLYLQMNSLRAADTALYYCVKDIRGIVATGGAFDIWGRGTMVTVSS (SEQ ID NO: 755) VHEVQLVESGGGLVQPGGSLRLSCAASGFTVGTNYMNWVRQAPGKGLEWISVIYSGGSTFYADSVKGRFTISRQTSQNTLYLQMNSLRPEDTAVYYCARGIRGFDIWGQGTMVTVSS (SEQ ID NO: 756) VHEVQLVESGGGLVQPGGSLRLSCAASGFTISTNYMNWVKQAPGKGLEWVAVIYSSGSTYYIDSVKGRFTISRLTSKNTVYLQMSSLNSEDTAVYYCARGIRGFDIWGQGTMVTVSS (SEQ ID NO: 757) VHEVQLVESGGGLVQPGRSLRLSCAASGFTIDDSAMHWVRQTPGKGLEWVSGISWKSGSIGYADSVRGRFTISRDNAKNSLYLQMNSLRVEDTALYYCVKDIRGNWNYGGNWFDPWGQGTLVTVSS (SEQ ID NO: 758) VHEVQLVESGGGLVQPGGSLRLSCEASGFTVGVNHMNWVRQAPGKGLEWVSVIFSSGRTFYGDYVKGRLTIFRQTSQNTVYLQMNSLRSEDTAIYYCARGIGGLDIWGRGTMVTVSS (SEQ ID NO: 759) VHEVQLVESGGGLVQPGRSLRLSCAASGFTFDDYALHWVRQAPGKGLEWVSGISWTGGTIDYADSVKGRFTISRDNAKNSLYLQMSSLRTEDTAIYYCTRDIRGNWKYGGWFDPWGQGTLVTVSS (SEQ ID NO: 760) VHQVQLVQSGTEVKKPGASVKVSCKASGYTFTAYYMHWVRQAPGQGLDWMGWISPNSGFTNYAQKFQGRVTMTRDTSINTFYMELSGLRSDDTAVYYCAREGSTHHNSFDPWGQGTLVTVSS (SEQ ID NO: 761) VHEVQLVESGGGLVQPGGSLRLSCAASGFTVGTNFMNWVRQAPGKGLEWVSAIYSGGTANYADSVKGRFTISRDTSRNTLYLQMNSLRTEDTAVYYCARGGGMDVWGQGTTVTVSS (SEQ ID NO: 762) VHQVQLVQSGAEVKKPGSSVKVSCKASGGTFNTYVLSWVRQAPGQGLEWMGEIIPILGAANYAQNFQGRVTFTTDESTNTAYMDLSSLRSEDTAVYYCARDRTSGGFDPWGQGTLVTVSS (SEQ ID NO: 763) VHQVQLVQSGAEVEKPGASVKVSCKASGYIFTHYGISWVRQAPGQGLEWVGWISPYNGYTDYAQKLQGRVTLTTDTSTTTAYMELRNLRSDDTAMYYCSRGRGPYWSFDLWGRGTLVTVSS (SEQ ID NO: 764) VLDIQMTQSPSTLSASVGDRVTITCRASQSISNWLAWYQQKPGKAPKLLIYKASSLESGVPSRFSGSGSGTEFTLTISSLQPDDFATYYCQQYHSYSYTFGQGTKEIK (SEQ ID NO: 765) VLDIQMTQSPSSLSASVGDRVTITCRASQGIRNDLGWYQQKPGKAPKRLIYTASSLQSGVPSRFSGSGSGTEFTLTISSLQPEDFATYYCLQHNSYPLTFGGGTKVAIK (SEQ ID NO: 766) VLDIQMTQSPSSLSASVGDRVTITCRTSQGIRNDLGWYQQKPGKAPKRLIYAASSLQSGVPSRFSGSGSGTEFTLTISSLQPEDFATYYCLQHNNYPYTFGQGTKLEIK (SEQ ID NO: 767) VLDIVMTQTPLSSPVTLGQPASISCRSSQTLVHGDGNTYLSWIQQRPGQPPRLLIYKVSNQFSGVPDRFSGSGAGTDFTLKISRVEAEDVGLYFCMQATHFPITFGQGTRLEIK (SEQ ID NO: 768) VLDIVMTQTPLSSPVTLGQPASISCRSSPSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQATHFPITFGQGTRLEIR (SEQ ID NO: 769) VLDIQMTQSPSSLSASLGDRVTITCRASQSINSYLNWYQQKPGKAPKLLIYVASSLQSGVPSRFSGSGSGTEFTLTISNLQPEDFATYYCQQSYSTPPITFGQGTRLEIK (SEQ ID NO: 770) VLDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYVASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYSTPPITFGQGTRLEIK (SEQ ID NO: 771) VLDIQMTQSPSSLSASVGDRVTITCRASQTINIYLNWYQQKPGRAPRLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCHQSYSTPPITFGQGTRLEIK (SEQ ID NO: 772) VLDIQMTQSPSSLSASVGDRVTITCRASQSMSSYLNWYQQKPGRAPKLLIFAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYSTPPITFGQGTRLEIK (SEQ ID NO: 773) VLEIVLTQSPGTLSLSPGERATLSCRASQSFNFNYLAWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTINRLEPEDFGVFYCQQYESAPWTFGQGTKVEIK (SEQ ID NO: 774) VLDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKLLIYAASSLQSGVPSRFSGGGSGTDFTLTISSLRPEDFATYYCQQSYCTPPITFGQGTRLEIK (SEQ ID NO: 775) VLDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYSTPPITFGQGTRLEIK (SEQ ID NO: 776) VLDRVTITCRASQVISNYLAWYQQKPGKVPRLLIYAASTLQSGVPSRFSGSGSGTDFTLTISSLQPEDVATYYCQKYNSAPRTFGQGTKVEIK (SEQ ID NO: 777) VLDIQMTQSPSSLSASVGDRVTITCRASQNINNYLNWYQQKPGKAPKLLIYAASSFQNAVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYNTPLTFGGGTKVEIK (SEQ ID NO: 778) VLDIQMTQSPSSLSASVGDRVTITCRASQGIRNDLGWYQQKPGKAPKRLIYAASSLQSGVPSRFSGSGSGTEFTLTISSLQPEDFATYYCLQHNSYPYTFGQGTKLEIK (SEQ ID NO: 779) VLDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYSTPPITFGQGTRLEIK (SEQ ID NO: 780) Group M VHQSLEESGGRLVKPDETLTITCTVSGIDLSSNGLTWVRQAPGEGLSWIGTINKDASAYYASWAKGRLTISKPSSTKVDLKITSPTTEDTATYFCGRIAFKTGTSIWGPGTLVTVSS (SEQ ID NO: 1108) VLAIVMTQTPSPVSAAVGGTVTINCQASESVYSNNYLSWFQQKPGQPPKLLIYLASTLASGVPSRFKGSGSGTQFTLTISGVQCDDAATYYCIGGKSSSTDGNAFGGGTEVVVR (SEQ ID NO: 1109) Group N VHQMQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGTANYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARGNIVATITPLDYWGQGTLVTVSS (SEQ ID NO: 1110) VHQPVLTQPPSVSAAPGQKVTISCSGSSSNIANNYVSWYQQLPGTAPKLLIFANNKRPSGIPDRFSGSKSGTSAALDITGLQTGDEADYYCGTWDSDLRAGVFGGGTKLTVL (SEQ ID NO: 1111) VHEVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGTANYAQKFQGRVTITADKSTSTAYMELSSLRSEDTAVYYCAREGTIYDSSGYSFDYWGQGTLVTVSS (SEQ ID NO: 1112) VHQVQLVESGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 1113) VHEVQLVESGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 1114) VHQVQLVESGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 1115) VHEVQLVESGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 1116) VHEVQLVESGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 1117) VHQVQLVESGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 1118) VHQVQLVQSGAEVKKPGSSVKVSCKASGGTFSRYGVHWVRQAPGQGLEWMGRLIPIVSMTNYAQKFQDRVSITTDKSTGTAYMELRSLTSEDTALYYCASVGQQLPWVFFAWGQGTLVTVSS (SEQ ID NO: 1119) VHQMQLVQSGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 1120) VHQVQLVQSGGGVVQPGRSLRLSCAASGFTFSSYAMHWVRQAPGKGLEWVAVISFDGSNKYYADSVRGRFTISRDNSKNTLYLQMNSLRTEDTAVYYCARGWLDRDIDYWGQGTLVTVSS (SEQ ID NO: 1121) VHQMQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAYSWVRQAPGQGLEWMGGIIPSFGTANYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARGPIVATITPLDYWGQGTLVTVSS (SEQ ID NO: 1122) VHQMQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAYSWVRQAPGQGLEWMGGIIPIFGTANYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARGPIVATITPLDYWGQGTLVTVSS (SEQ ID NO: 1123) VHQMQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAYSWVRQAPGQGLEWMGGIIPSFGTANYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARGPIVATITPLDYWGQGTLVTVSS (SEQ ID NO: 1124) VHQMQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGGIIPAFGTANYAQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARGPIVATITPLDYWGQGTLVTVSS (SEQ ID NO: 1125) VLSYELMQPPSVSVAPGKTATIACGGENIGRKTVHWYQQKPGQAPVLVIYYDSDRPSGIPERFSGSNSGNTATLTISRVEAGDEADYYCQVWDSSSDHRIFGGGTKLTVL (SEQ ID NO: 1126) VLAIRMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYTTSSLKSGVPSRFSGSGSGTDFTLTISRLQPEDFATYYCQQSYSSTWTFGRGTKVEIK (SEQ ID NO: 1127) VLQSVLTQPPSVSAAPGQKVTISCSGNNSNIANNYVSWYQQLPGTAPKLLIYDNNYRPSGIPDRFSGSKSGTSATLDITGLQTGDEADYYCGVWDGSLTTGVFGGGTKLTVL (SEQ ID NO: 1128) VLLPVLTQPASVSGSPGQSITISCTGTTSDIGGYDYVSWYQQHPGKAPKLMIYDVSKRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSSSTHVFGTGTKLTVL (SEQ ID NO: 1129) VLQSALTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSNRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYRSSTLGPVFGGGTKLTVL (SEQ ID NO: 1130) VLQAGLTQPPSVSEAPRQRVTISCSGSSSNIGNNAVNWYQQLPGKAPKLLIYYDDLLPSGVSDRFSGSKSGTSASLAISGLQSEDEADYYCAAWDDSLNGYVFGTGTKLTVL (SEQ ID NO: 1131) VLQSALTQPRSVSGSPGQSVTISCTGTSSDVGGYNYVSWYQQHPGKAPKLMIYDVSKRPSGVPDRFSGSKSGNTASLTISGLQAEDEADYYCSSYTSSTTHVFGTGTKVTVL (SEQ ID NO: 1132) VLQSVVTQPPSVSAAPGQKVTISCSGSSSNIGNNYVSWYQQLPGTAPKLLIYDNNKRPSGIPDRFSGSKSGTSATLGITGLQTGDEADYYCGTWDSSLSVWVFGGGTQLTVL (SEQ ID NO: 1133) VLQSVLTQPASVSGSPGQSITISCTGTSSDVGGYNYVSWYQQHPGRAPRLMIYDVSNRPSGVSNRFSGSKSGNTASLTISGLQAEDEGDYYCSSYTSGGTLGPVFGGGTKLTVL (SEQ ID NO: 1134) VLQSVVTQPPSVSAAPGQKVTISCSGSSSNIGNNYVSWYQQLPGTAPKLLIYDNNKRPSGIPDRFSGSKSGTSATLGITGLQTGDEADYYCGTWDSSLSAVVFGGGTKLTVL (SEQ ID NO: 1135) VLQSVVTQPPSVSAAPGQKVTISCSGSSSNIGNNYVSWYQQVPGTAPKLLIYDNNKRPSGIPDRFSGSNSDTSATLGITGLQTGDEADYYCGTWDSSLSAWVFGGGTKLTVL (SEQ ID NO: 1136) VLQSVVTQPPSVSAAPGQKVTISCSGSSSNIGNNYVSWYQQLPGTAPKLLIYDNNKRPSGIPDRFSGSKSGTSATLGITGLQTGDEADYYCGTWDSSLSAGSVVFGGGTKLTVL (SEQ ID NO: 1137) VLSYELMQPPSVSVAPGKTATIACGGENIGRKTVHWYQQKPGQAPVLVIYYDSDRPSGIPERFSGSNSGNTATLTISRVEAGDEADYYCLVWDSSSDHRIFGGGTKLTVL (SEQ ID NO: 1138) VLSYELMQPPSVSVAPGKTATIACGGENIGRKTVHWYQQKPGQAPVLVIYYDSDRPSGIPERFSGSNSGNTATLTISRVEAGDEADYYCQVWDSSSDHRIFGGGTKLTVL (SEQ ID NO: 1139) VLSYELMQPPSVSVAPGKTATIACGGENIGRKTVHWYQQKPGQAPVLVIYYDSDRPSGIPERFSGSNSGNTATLTISRVEAGDEADYYCQVWDSSSDHRIFGGGTKLTVL (SEQ ID NO: 1140) VLSYELMQPPSVSVAPGKTATIACGGENIGRKTVHWYQQKPGOAPVLVIYYDSDRPSGIPERFSGSNSGNTATLTISRVEAGDEADYYCQVWDSSSDHRIFGGGTKLTVL (SEQ ID NO: 1141) Group O VHQVQLVQSGSEVKKSGSSVKVSCKTSGGTFSITNYAINWVRQAPGQGLEWMGGILPIFGAAKYAQKFQDRVTITADESTNTAYLELSSLTSEDTAMYYCARGKRWLQSDLQYWGQGTLVTVSS (SEQ ID NO: 1142) VLQPVLTQPASVSGSPGQSITISCTGSSSDVGSYDLVSWYQQSPGKVPKLLIYEGVKRPSGVSNRFSGSKSGNTASLTISGLQAEDEADYYCSSYAGTRNFVFGGGTQLTVL (SEQ ID NO: 1143) Note that thesequences provided for Group J are heavy chain and light chain aminoacid sequences; the sequences provided for Group K include variableheavy chain, variable light chain, heavy chain, and light chain aminoacid sequences, all other sequences presented in Table 15 are variableheavy chain and variable light chain sequences

In some embodiments, the activatable anti-PDL1 antibody includes a heavychain that comprises or is derived from a heavy chain amino acidsequence shown in U.S. Pat. Nos. 7,943,743; 8,779,108; 8,217,149;8,460,927; 7,794,710; 8,741,295; and 8,981,063; in US Patent ApplicationPublication Nos. 2014356353; 20130323249; 2014341917; 20130309250;20110280877; and 20090317368 (now issued as U.S. Pat. No. 8,981,063listed above); and in PCT Publication Nos. WO2014/100483; WO2012/145493;WO2014/100439; WO2014/195852; WO2014/100079; WO2013/173223; andWO2014/55897, the contents of each of which are hereby incorporated byreference in their entirety. In some embodiments, the activatableanti-PDL1 antibody includes a light chain that comprises or is derivedfrom a light chain amino acid sequence shown in U.S. Pat. Nos.7,943,743; 8,779,108; 8,217,149; 8,460,927; 7,794,710; 8,741,295; and8,981,063; in US Patent Application Publication Nos. 2014356353;20130323249; 2014341917; 20130309250; 20110280877; and 20090317368 (nowissued as U.S. Pat. No. 8,981,063); and in PCT Publication Nos.WO2014/100483; WO2012/145493; WO2014/100439; WO2014/195852;WO2014/100079; WO2013/173223; and WO2014/55897, the contents of each ofwhich are hereby incorporated by reference in their entirety. In someembodiments, the activatable anti-PDL1 antibody includes a heavy chainand a light chain that comprise or are derived from a heavy chain aminoacid sequence and a light chain amino acid sequence shown in U.S. Pat.Nos. 7,943,743; 8,779,108; 8,217,149; 8,460,927; 7,794,710; 8,741,295;and 8,981,063; in US Patent Application Publication Nos. 2014356353;20130323249; 2014341917; 20130309250; 20110280877; and 20090317368 (nowissued as U.S. Pat. No. 8,981,063); and in PCT Publication Nos.WO2014/100483; WO2012/145493; WO2014/100439; WO2014/195852;WO2014/100079; WO2013/173223; and WO2014/55897, the contents of each ofwhich are hereby incorporated by reference in their entirety.

In some embodiments, the activatable antibody includes an anti-PDL1antibody that includes at least one CDR sequence selected from the CDRsequences (VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2, VL CDR3) fromthe CDR sequences recited in U.S. Pat. No. 7,943,743. In someembodiments, the activatable antibody includes an anti-PDL1 antibodythat includes at least one CDR, at least two, at least three, at leastfour, at least five, and/or six CDR sequences selected from thefollowing sequences in U.S. Pat. No. 7,943,743; SEQ ID NO: 21, SEQ IDNO: 31, SEQ ID NO: 41, SEQ ID NO: 51, SEQ ID NO: 61, and SEQ ID NO: 71.In some embodiments, the activatable antibody includes an anti-PDL1antibody that includes at least one CDR, at least two, at least three,at least four, at least five, and/or six CDR sequences selected from SEQID NO: 22, SEQ ID NO: 32, SEQ ID NO: 42, SEQ ID NO: 52, SEQ ID NO: 62,and SEQ ID NO: 72. In some embodiments, the activatable antibodyincludes an anti-PDL1 antibody that includes at least one CDR, at leasttwo, at least three, at least four, at least five, and/or six CDRsequences selected from SEQ ID NO: 23, SEQ ID NO: 33, SEQ ID NO: 43, SEQID NO: 53, SEQ ID NO: 63, and SEQ ID NO: 73.

In some embodiments, the activatable antibody includes an anti-PDL1antibody that includes at least one CDR, at least two, at least three,at least four, at least five, and/or six CDR sequences selected from thefollowing sequences in U.S. Pat. No. 7,943,743; a VH CDR1 sequencecomprising SEQ ID NO: 21, SEQ ID NO: 22, or SEQ ID NO: 23; a VH CDR2sequence comprising SEQ ID NO: 31, SEQ ID NO: 32, or SEQ ID NO: 33; a VHCDR3 sequence comprising SEQ ID NO: 41, SEQ ID NO: 42, or SEQ ID NO: 43;a VL CDR1 sequence comprising SEQ ID NO: 51, SEQ ID NO: 52, or SEQ IDNO: 53; a VL CDR2 sequence comprising SEQ ID NO: 61, SEQ ID NO: 62, orSEQ ID NO: 63; and a VL CDR3 sequence comprising SEQ ID NO: 71, SEQ IDNO: 72, or SEQ ID NO: 73.

In some embodiments, the activatable antibody includes an anti-PDL1antibody that binds a polypeptide that comprises or is derived from SEQID NO: 1 or SEQ ID NO: 3 of U.S. Pat. No. 8,460,927.

In some embodiments, the activatable antibody includes an anti-PDL1antibody that binds a human PDL1 polypeptide that comprises or isderived from SEQ ID NO: 1 of U.S. Pat. No. 8,460,927:

(SEQ ID NO: 585) MRIFAVFIFMTYWHLLNAFTVTVPKDLYVVEYGSNMTIECKFPVEKQLDLAALIVYWEMEDKNIIQFVHGEEDLKVQHSSYRQRARLLKDQLSLGNAALQITDVKLQDAGVYRCMISYGGADYKRITVKVNAPYNKINQRILVVDPVTSEHELTCQAEGYPKAEVIWTSSDHQVLSGKTTTTNSKREEKLFNVTSTLRINTTTNEIFYCTFRRLDPEENHTAELVIPELPLAHPPNERTHLVILGAILLCLGVALTFIFRLRKGRMMDVKKCGIQDTNSKKQSDTHLEET

In some embodiments, the activatable antibody includes an anti-PDL1antibody that binds a murine PDL1 polypeptide that comprises or isderived from SEQ ID NO: 3 of U.S. Pat. No. 8,460,927:

(SEQ ID NO: 586) MRIFAGIIFTACCHLLRAFTITAPKDLYVVEYGSNVTMECRFPVERELDLLALVVYWEKEDEQVIQFVAGEEDLKPQHSNFRGRASLPKDQLLKGNAALQITDVKLQDAGVYCCIISYGGADYKRITLKVNAPYRKINQRISVDPATSEHELICQAEGYPEAEVIWTNSDHQPVSGKRSVTTSRTEGMLLNVTSSLRVNATANDVFYCTFWRSQPGQNHTAELIIPELPATHPPQNRTHWVLLGSILLFLIVVSTVLLFLRKQVRMLDVEKCGVEDTSSKNRNDTQFEET

In some embodiments, the activatable antibody includes an anti-PDL1antibody that binds a polypeptide that comprises or is derived from SEQID NO: 36 or SEQ ID NO: 38 of PCT Publication No. WO 2014/10079.

In some embodiments, the activatable antibody includes an anti-PDL1antibody that binds a human PDL1 polypeptide that comprises or isderived from SEQ ID NO: 36 of PCT Publication No. WO 2014/10079.

(SEQ ID NO: 587) MRIFAVFIFMTYWHLLNAFTVTVPKDLYVVEYGSNMTIECKFPVEKQLDLAALIVYWEMEDKNIIQFVHGEEDLKVQHSSYRQRARLLKDQLSLGNAALQITDVKLQDAGVYRCMISYGGADYKRITVKVNAPYNKINQRILVVDPVTSEHELTCQAEGYPKAEVIWTSSDHQVLSGKTTTTNSKREEKLFNVTSTLRINTTTNEIFYCTFRRLDPEENHTAELVIPELPLAHPPNERTHLVILGAILLCLGVALTFIFRLRKGRMMDVKCGIQDTNSKQSDTHLEET

In some embodiments, the activatable antibody includes an anti-PDL1antibody that binds a human PDL1 extracellular domain polypeptide thatcomprises or is derived from SEQ ID NO: 38 of PCT Publication No. WO2014/10079.

(SEQ ID NO: 588) FTVTVPKDLYVVEYGSNMTIECKFPVEKQLDLAALIVYWEMEDKNIIQFVHGEEDLKVQHSSYRQRARLLKDQLSLGNAALQITDVKLQDAGVYRCMISYGGADYKRITVKVNAPYNKINQRILVVDPVTSEHELTCQAEGYPKAEVIWTSSDHQVLSGKTTTTNSKREEKLFNVTSTLRINTTTNEIFYCTFRRLDPEE NHTAELVIPELPLAHPPNERT

In some embodiments, the activatable antibody includes an anti-PDL1antibody that is or is derived from BMS-936559 (MDX-1 105). In someembodiments, the activatable antibody includes an anti-PDL1 antibodythat is or is derived from MPDL3280A (RG7446). In some embodiments, theactivatable antibody includes an anti-PDL1 antibody that is or isderived from MED14736. In some embodiments, the activatable antibodyincludes an anti-PDL1 antibody that is or is derived from AMP224. Insome embodiments, the activatable antibody includes an anti-PDL1antibody that is or is derived from MSB0010718C.

In some embodiments, the activatable anti-PDL1 antibody comprises or isderived from an antibody that is manufactured, secreted or otherwiseproduced by a hybridoma, such as, for example, the hybridoma(s)disclosed in U.S. Pat. No. 8,779,108 and deposited at the NationalCollections of Industrial and Marine Bacteria (NCIMB) under depositnumber 41598, as well as the hybridoma(s) disclosed in U.S. Pat. No.8,741,295 and deposited at the Collection Nationale De Cultures DeMicroorganismes (CNCM) under deposit number I-4080, I-4081, and/orI-4122.

In some embodiments, the activatable anti-PDL1 antibody includes a CDRsequence shown in Table 16, a combination of VL CDR sequences (VL CDR1,VL CDR2, VL CDR3) selected from the group consisting of thosecombinations shown in a single row Table 16, a combination of VH CDRsequences (VH CDR1, VH CDR2, VH CDR3) selected from the group consistingof those combinations shown in Table 16, or a combination of VL CDR andVH CDR sequences (VL CDR1, VL CDR2, VL CDR3, VH CDR1, VH CDR2, VH CDR3)selected the group consisting of those combinations shown in Table 16.

TABLE 16 CDR Sequences for Antibodies andActivatable Antibodies that Bind PDL1 VL VH CDR2 CDR3 CDR1 AB CDR1(SEQ ID (SEQ ID (SEQ CDR2 CDR3 Name (SEQ ID NO) NO) NO) ID NO)(SEQ ID NO) (SEQ ID NO) C8 RASQSISSYLN KASRLQS RALKPVT SYAMSDITASGQRTTYADS SKAIFDY (209) (210) (211) (212) (213) (214) C12RASQSISSYLN AASSLQS SYSTPNT SYAMS SINKDGHYTSYADS NLDEFDY (209) (215)(216) (212) (217) (218) C16 RASQSISSYLN SASQLQS ANSRP3T SYAMSSIMATGAGTLYADS DGAGEDY (209) (219) (220) (212) (221) (222) C20RASQSISSYLN NASSLQS YPYGPG SYAMS TITSSGAATYYADS NYTGFDY (209) (223)(224) (212) (225) (226) C60 RASQSISSYLN YASTLQS DNGYPST SYAMSSIYSTGGATAYADS SSAGFDY (209) (227) (228) (212) (229) (230) C1RASQSISSYLN YASTLQS DNGYPST SYAMS SSIYSTGGATAYADS SSAGQSRPGFDY (209)(227) (228) (212) (231) (232) D1 RASQSISSYLN YASTLQS DNGYPST SYAMSSSIYSTGGATAYADS SSAGQSWPGFDY (209) (227) (228) (212) (231) (233) G7RASQSISSYLN YASTLQS DNGYPST SYAMS SSIYSTGGATAYADS SSAGQSFPGFDY (209)(227) (228) (212) (231) (234) H9 RASQSISSYLN YASTLQS DNGYPST SYAMSSSIYSTGGATAYADS WSAAFDY (209) (227) (228) (212) (231) (235) B10RASQSISSYLN YASTLQS DNGYPST SYAMS SSIYSTGGATAYADS WSAGYDY (209) (227)(228) (212) (231) (236) E10 RASQSISSYLN YASTLQS DNGYPST SYAMSSSIYSTGGATAYADS WSKGFDY (209) (227) (228) (212) (231) (237) A05RASQSISSYLN YASTLQS DNGYPST SYAMS SSIWKQGIVTVYDS SSAGFDY (209) (227)(228) (212) (238) (230) C05 RASQSISSYLN YASTLQS DNGYPST SYAMSSSIWRNGIVTVYDS SSAGFDY (209) (227) (228) (212) (239) (230) C10RASQSISSYLN YASTLQS DNGYPST SYAMS SDIWKQGMVTVYDS SSAGFDY (209) (227)(228) (212) (240) (230) D08 RASQSISSYLN YASTLQS DNGYPST SYAMSSSIWRQGLATAYDS SSAGFDY (209) (227) (228) (212) (241) (230) G09RASQSISSYLN YASTLQS DNGYPST SYAMS SEIVATGILTSYDS SSAGFDY (209) (227)(228) (212) (242) (230) G10 RASQSISSYLN YASTLQS DNGYPST SYAMSSSIGRQGLITVYDS SSAGFDY (209) (227) (228) (212) (243) (230) G12RASQSISSYLN YASTLQS DNGYPST SYAMS SSIWYQGLVTVYDS SSAGFDY (209) (227)(228) (212) (244) (230) E11 RASQSISSYLN YASTLQS DNGYPST SYAMSSDIWKQGFATADS SSAGFDY (209) (227) (228) (212) (245) (230) D01RASQSISSYLN YASTLQS DNGYPST SYAMS SSIWKQGIVTVYDS SSAGFDY (209) (227)(228) (212) (238) (230) H06 RASQSISSYLN YASTLQS DNGYPST SYAMSSSIWRQGLATAYDS SSAGFDY (209) (227) (228) (212) (241) (230) C5H9RASQSISSYLN YASTLQS DNGYPST SYAMS SSIWRNGIVTVYADS WSAAFDY (209) (227)(228) (212) (246) (235) C5B10 RASQSISSYLN YASTLQS DNGYPST SYAMSSSIWRNGIVTVYADS WSAGYDY (209) (227) (228) (212) (246) (236) C5E10RASQSISSYLN YASTLQS DNGYPST SYAMS SSIWRNGIVTVYADS WSKGFDY (209) (227)(228) (212) (246) (237) G12H9 RASQSISSYLN YASTLQS DNGYPST SYAMSSSIWYQGLVTVYADS WSAAFDY (209) (227) (228) (212) (247) (235) G12B10RASQSISSYLN YASTLQS DNGYPST SYAMS SSIWYQGLVTVYADS WSAGYDY (209) (227)(228) (212) (247) (236) G12E10 RASQSISSYLN YASTLQS DNGYPST SYAMSSSIWYQGLVTVYADS WSKGFDY (209) (227) (228) (212) (247) (237) C5H9RASQSISSYLN AASSLQS DNGYPST SYAMS SSIWRNGIVTVYADS WSAAFDY v2 (209) (215)(228) (212) (246) (235)

In some embodiments, the activatable anti-PDL1 antibody includes a CDRsequence shown in Table 17, a combination of VL CDR sequences selectedfrom the group consisting of those combinations shown in Table 17,and/or a combination of VH CDR sequences selected from the groupconsisting of those combinations shown in Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group A in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group A in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group A in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Ain Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group B in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group B in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group B in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Bin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group C in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group C in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group C in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Cin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group D in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group D in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group D in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Din Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group E in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group E in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group E in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Ein Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group F in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group F in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group F in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Fin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group G in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group G in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group G in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Gin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group H in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group H in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group H in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Hin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group I in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group I in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group I in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Iin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group J in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group J in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group J in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Jin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group K in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group K in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group K in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Kin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group L in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group L in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group L in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Lin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group M in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group M in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group M in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Min Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group N in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group N in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group N in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Nin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes acombination of heavy chain CDR sequences selected from the groupconsisting of the combinations shown in Group O in Table 17. In someembodiments, the activatable anti-PDL1 antibody includes a combinationof light chain CDR sequences selected from the group consisting of thecombinations shown in Group O in Table 17. In some embodiments, theactivatable anti-PDL1 antibody includes a combination of heavy chain CDRsequences selected from the group consisting of the combinations shownin Group O in Table 17, and a combination of light chain CDR sequencesselected from the group consisting of the combinations shown in Group Oin Table 17.

In some embodiments, the activatable anti-PDL1 antibody includes a heavychain CDR1 sequence selected from the group consisting of the sequencesshown in Group P in Table 17.

TABLE 17 Additional CDR Sequences for Antibodies andActivatable Antibodies that Bind PDL1 VL VH CDR1 CDR2 CDR3 CDR1 CDR2CDR3 (SEQ ID NO:) (SEQ ID NO:) (SEQ ID NO:) (SEQ ID NO:) (SEQ ID NO:)(SEQ ID NO:) Group A RASQSVSSYLV DASNRAT QQRSNWPRT DYGFSWITAYNGNTNYAQKLQG DYFYGMDV (304) (293) (278) (296) (284) (269)RASQSVSSYLA AASSLQS QQRSNWPT TYAIS GIIPIFGKAHYAQKFQG KFHFVSGSPFGMDV(305) (215) (279) (297) (285) (270) RASQGISSWLA GASSRAT QQYNSYPYT SYDVHWLHADTGITKFSQKFQG ERIQLWFDY (306) (294) (280) (298) (286) (271)RASQSVSSSYLA DASSLES QQYGSSPWT TYAIN GIIPIFGTANHAQKFQG DQGIAAALFDY (307)(295) (281) (299) (287) (272) RASQGISSALA KASTLES QQYGSSP DYVVHGISGNSGNIGYADSVKG PFDY (308) (447) (282) (300) (288) (273) QQFNSYPETSYAIS GIIPIFGRAHYAQKFQG KYDYVSGSPFGMDV (283) (301) (289) (274) QQSYSTPWTSYAIN GIIPIFGSANYAQKFQD DSSGWSRYYMDV (448) (302) (290) (275) DYGMHGIIPLFGIAHYAQKFQG KYSYVSGSPFGMDV (303) (291) (276) GISWNRGRIEYADSVKGGRFRYFDWFLDY (292) (277) DYFWSGFSAFDI (446) Group B SGDALPQKYVF EDSKRPSYSTDRSGNHRV TYSMN SISSSGDYIYYADSVK DLVTSMVAFDY (312) (313) (314) (309)(310) (311) RASQRVSSSYLA DASSRAT QQYGSLPWT RYWMS NIKQDGSEKYYVDSVKGEGGWFGELAFDY (318) (319) (320) (315) (316) (317) RASQSVSSNYLA GTSSRATQQYGSSIFT SYWMS NIKQDGGEQYYVDSVK DWNYGYYDMDV (324) (325) (326) (321)(322) (323) Group C RASQ(D/V) SAS(F/T) QQ(Y/G/F/S) GFTFS(D/G)AWI(S/L)PYGGS(T/S) RHWPGGFDY (V/I)(S/N)T L(Y/A)S (L/Y/F/W)(Y/ SWIHYYADSVKG (332) (A/F)(V/L)A (328) N/A/T/G/F/ (330) (331) (327)I)(H/V/P/T/ I)P(A/W/R/P/ T)T (329) RASQDVSTAVA SASFLYS QQYLYHPATGFTFSDSWIH AWISPYGGSTYYADSVKG (333) (334) (335) (336) (337) Group DKSSOSLL WASTRES (Q/K)QSYDVVT SYW(I/M)H YINPSS(D/G)Y(H/K)E SGWL(I/V)(H/N)(S/T) (589) (590) (591) Y(S/N)(E/Q)KF(I/M) HGDYYFD(F/ (R/S)TRKNYLAD (592) Y) (593) (588) KSSQSLLNSRT QQSYDVVT SYWMH YINPSSDYNEYSEKFMDSGWLVHGDY RKNYLA (595) (596) (597) YFDY (594) (598) KSSQSLLHTST KQSYDVVTGYIFTSYWMH YINPSSGYHEYNQKFID SGWLIHGDY RKNYLA (600) (601) (602) YFDF(599) (603) SYWIH (604) GTTFTSYWIH (605) Group E TGT(N/S)(T/ (E/D)V(I/SS(F/Y)T(N/ (K/R/T/Q/G/ SIYPSGG(F/I)TFYAD IKLGTVTTV R/S)DVG(A/G) N/D)(D/S)(R/T/S)(G/ A/W/M/I/S) (S/T)VKG (610) (E/D)Y YNYVS H/N)RPS S)(I/T)RVY(V/R/K/L/ (611) (606) (607) (608) M/I)M(H/T/ N/Q/A/V/Y/ W/F/M) (609)TGTSSDVGGYN DVSNRPS SSYTSSSTRV SYIMM SIYPSGGITFYADTVKG IKLGTVTTVYVS (612) (613) (614) (615) (617) DY (618) Group F MYMMMSIYPSGGITFYADSVKG TGTSSDVGA (619) (620) YNYVS (621) Group G (R/S/K)(A/S)X(A/C/G/ (R/N/Q/E/H) G(Y/F)(T/S) X(I/L/M/F/V)X(P or (A/R/N/Q/S (R/N/D/Q/ S/T/V)(A/ QX(A/R/N/C/ (I/L/M/F) Absent)(A/R/N/Q/E/E/H/K/M/S/ E/H/K/M/S) C/H/I/L/ Q/E/H/I/L/K/ (A/R/N/D/C/H/K/M/S/T/Y/V)(A/R/ T/Y)(A/R/ (SLLYSS or M/F/S/T/ M/F/S/T/Y/ Q/E/H/I/L/N/D/C/Q/E/G/H/K/M/ N/D/C/Q/ Absent)(N/D Y/V)(R/ V)(N/G/S)(A/ K/M/P/S/T/F/P/S/T/Y/V)(N/G/ E/G/H/K/M/ or N/D/Q/E/ R/N/D/C/Q/ W/Y/V)(N/S)(N/G/S)T(A/R/N/Q/ F/P/S/T/ Absent)(A/Q/ K/S/T)(A/ E/G/H/I/L/K/D/Q/E/K/P/ E/H/K/M/S/T/Y)(A/ Y/V)(Q/G/ E/L/K/M/P/ R/N/D/Q/ M/F/R/S/T/S/T)(A/R/N/ R/N/C/Q/E/H/I/L/K/ H/T/W)XXX S/T/Y/V)X(R/ E/G/H/K/W/Y/V)P(A/R/ D/C/Q/E/G/ M/F/S/T/W/Y/V)N(A/ X(F/Y)(AI N/S/T)(A/R/M/F/P/S/ N/D/Q/E/G/ H/I/L/K/M/ D/Q/E/K/P/S/T)(A/R/ or N/C/Q/E/H/ T/Y)(A/H/K/M/P/S/T/ F/P/S/T/Y/ N/D/C/Q/E/G/H/I/L/ Absent) I/L/K/M/F/S/ N/S/T)Y) T (624) V)(A/R/N/ K/M/F/P/S/T/Y/V) (627) T/Y/V)(I/L/ (623) D/C/Q/E/G/(I/L/M/F)K(A/G/S M/V)(A/R/N/ H/I/L/K/M/ (626) Q/E/H/I/K/ F/P/S/T/Y/M/F/S/T/Y) V)(A/R/C/Q/ (622) E/H/I/L/K/ M/F/S/T/W/ Y/V)N (625)RASSSVSYIY ATFNLAS HQRSSYPWT GYTFPDYYMN DIDPNYGGTTYNQKFKG GAL (633)(628) (629) (630) (631) (632) SASSSIRYMH DTSKLTS QQDSSYPLT GYTFTSYDINWIFPRDNNTKYNSNFKG ENWVGDF (634) (635) (636) (637) (638) (639)KASQDVGTAVA WASTRHT QQYYGYPLT GYSITSDYWN YISYTGSTYYNPSLKS YGGWLSPF (640)(641) (642) (643) (644) (645) KSSQSLLYSSN WASTRES GYSIISDYWN RGGWLLPFQKNSL (646) (589) (647) (648) GFSLTTYSIN VMWAGGGTNSNSVLKS YYGNSPYYA(649) (650) I (651) Group H TRSSGSIGSNY EDNQRPS QSYD3STWV SYAISWISPIGGSTNYAQKVQG GLXXXXXXX VQ (652) (653) (654) (301) (655) XXXXXXXXDV (656) TRSSGNIASNY GKNNRPS QSYDSSNLWV SYGIS WISAYNGNTNYAQKLED ALPSGTILVVQ (657) (658) (659) (660) (661) GGWFDP (662) QGDSLRSYYAS SDRDRPSNSRDSSGNHYV SYALS AISGGGGSTYYADSVKD DVFPETFSM (663) (664) (665) (666)(667) NYGMDV (668) GGSDIGRKSVH DVSNRPS QVWDNNSDHYV DYAMHLISGDGGSTYYADSVKD VLLPCSSTS (669) (613) (670) (671) (672) CYGSVGAFDI (673) TGTSSDVGGYN GASSRAT SSYTSSTLP NYDMS RVNWNGGSTTYADAVKD EFVGAIDLYVS (612) (294) (674) (675) (676) (677) RASQSIGNSLA AASTLQS QQHTIPTESGLYIH WIIPIEGTANYAQKFED GLRWGIWGW (678) (679) (680) (681) (682)FDP (683) RASQGIGSYLA QDIKRPS QQLNNYPIT DNAIS WIIPIFGKPNYAQKFEDTMVRGFLGV (684) (685) (686) (687) (688) MDV (689) SGDKLGNKYAY EDYRRPSQTWDNSVV SYAMS AISGSGGSTYYADSVKD DQFVTIFGV (690) (691) (692) (212) (693)PRYGMDV (694) TRSSGSIDSNY DDSDRPS QSYDSNNRHVI TYALN RIVPLIGLVNYAHNFEDGRQMFGAGI VQ (695) (696) (697) (698) (699) DF (700) TRSSGNIGTNY EDNKRPSQSYHSSGWE SHGIT WISAHNGHASNAQKVED EVYGGNSDY VQ (701) (702) (703) (704)(705) (706) GGNNIGSKGVH YKSDSNKQ QVWDSSSDHWV RHGMH VISHDGSVKYYADSMKDVHAALYYGM (707) QAS (709) (710) (711) DV (712) (708) TRSSGSIASNYQSYDSTTPSV WTSPHNGLTAFAQILED GLSYQVSGW VQ (713) (714) (715) FDP (716)TRSSGSIASHY QSYDGITVI RIIPILGIANYAQKFED VHPVFSYAL VQ (717) (718) (719)DV (720) TLRSGLNVGSY QSYDSSNRWV TYAFS WISAYNGNTNYAQKVED DGYGSDPVLRIY (721) (722) (723) (724) (725) MIWYSSAVV NYGIS GDFRKPFDY (726) (727)(728) Group I RATESVEYYGT AASSVDS QQSRRVPYT SYVMH YVNPENDGTKYNEMFKGQAWGYP SLVQ (729) (730) (731) (732) (733) (734) Group J RASQDVSTAVASASFLYS QQYLYHPAT GFTFSDSWIH AWISPYGGSTYYADSVKG RHWPGGFDY (333) (334)(335) (336) (337) (332) Group K QSISNW KAS QQYHSYSYT GFTFSRFWINQDGTEK (785) ANTYYDFWSGHFD (781) (782) (783) (784) Y (786) QGIRND TASLQHNSYPLT GFTFSNFG LWSDGSNK (791) ARGRGAPGIPIFG (787) (788) (789) (790)Y (792) QGIRND AAS LQHNNYPYT GFTFSNAW IKRKTDGGTT TTDDIVVVPAVMR (787)(793) (794) (795) (796) EYYFGMDV (797) QTLVHGDGNTY KVS MQATHFPITGYSFTGYY INPNSGTK (802) ARDEDWNFGSWFD (798) (799) (800) (801) S (803)PSLVHSDGNTY KIS MQATHFPIT GYTFTGYY LNPNTGTT (807) ARDEDWNYGSWFD (804)(805) (800) (806) T (808) QSINSY VAS QQSYSTPPIT GFTFDDYG IHWHGKRT (813)VRGGMSTGDWFDP (809) (810) (811) (812) (814) QSISSY VAS QQSYSTPPITGFTFDDYG IHWSGRST (816) ARGGMSTGDWFDP (815) (810) (811) (812) (817)QTINIY AAS HQSYSTPPIT GFTVGSNY IYSGGST (821) ARGIRGLDV (818) (793) (819)(820) (822) QSMSSY AAS QQSYSTPPIT GITVGTNY ISSGGNT (1013) ARGIRGLDV(1011) (793) (811) (1012) (822) QSFNFNY GAS QQYESAPWT GGIFSSSTIIPVFGTV (827) ARNWGLGSFYI (823) (824) (825) (826) (828) QSISSY AASQQSYCTPPIT GFPFDEYA ISWSNNNI (831) AKSGIFDS (815) (793) (829) (830)(832) QSISSY AAS QQSYSTPPIT GFTFSSYG ISYEGRNK (834) AKDRTLYGMDV (815)(793) (811) (833) (835) QVISNY AAS QKYNSAPRT GFSLSTNRMC IDWDGVK (839)ARSTSLTFYYFDY (836) (793) (837) (838) (840) QNINNY AAS QQSYNTPLTEFTVGTNH IYSGGNT (844) ARGLGGMDV (841) (793) (842) (843) (845) QTISTYAAS LQHNSYPYT GFTFSKYW IKGDGSEK (849) ARDYWGSGYYFDF (846) (793) (847)(848) (850) QSISSY VVS QQSYSTPFT GFTFSSYW IKQDGSEK (854) ARDDIVVVPAPMG(815) (851) (852) (853) YYYYYFGMDV (855) AAS QQSYSTPPIT GFTFDDFAISWTGGNM (857) VKDIRGIVATGGA (793) (811) (856) FDI (858) GFTVGTNYIYSGGST (821) ARGIRGFDI (859) (860) GFTISTNY IYSSGST (862) ARGIRGFDI(861) (860) GFTIDDSA ISWKSGSI (864) VKDIRGNWNYGGN (863) WFDP (865)GFTVGVNH IFSSGRT (867) ARGIGGLDI (866) (868) GFTFDDYA ISWTGGTI (870)TRDIRGNWKYGGW (869) FDP (871) GYTFTAYY ISPNSGFT (873) AREGSTHHNSFDP(872) (874) GFTVGTNF IIPILGAA (876) ARGGGMDV (875) (877) GGTFNTYVISPYNGYT (879) ARDRTSGGFDP (878) (880) GYIFTHYG SPGRGPYWSFDL (881) (882)Group L QASESVYSNNY LASTLAS IGGKSSSTDG SNGLT TINKDASAYYASWAK IAFKTGTSILS (1014) (1015) NA (1016) (1017) G (1018) (1019) Group M RSSKSLLHSNGQMSNLAS AQNLEPPLT DYYTH WIDPENGKTAYAPKF GGYDVYFLDY ITYLY (1021) (1022)(1023) QG (1024) (1025) (1020) Group N KASQDVGIVVA WASIRHT QQYSNYPLYTGFSLTSYGVH VIWAGGSTNYNSALM AKPYGNSAMDY (1026) (1027) (1028) (1029)S (1030) (1031) VIWAGGSTNYVDSVK AKPYGTSAMDY G (1032) (1033)VIWAGGSTNYADSVK G (1034) Group O ASQSVSTSSSS YASNLES QHSWEIPYT SYGMSSISSGGSTYYPDSVK GYDSGFAY FMH (1035) (1036) (1037) (1038) G (1039) (1040)RASQSVSTSSS YASNLES QHSWEIPYT SYGMS SISSGGTTYYPDSVK GYDSGFAY SYMH (1041)(1036) (1037) (1038) G (1042) (1040) KASQSVSNDVA YAANRYT QQDYTSPYT TYGVHVIWRGVTTDYNAAFM LGFYAMDY (1043) (1044) (1045) (1046) AS (1047) (1048)KASQSVSNDVG YASNRYS QQDYTSPYT SYGVH VIWSGGVTDYNAAFI LGFYAMDY (1049)(1050) (1045) (1051) S (1052) (1048) RSSQIIVHSNA KVSNRFS FQGSHVPYT TYWMHQINPDSTTINTAPSL PGDYGYDFDC NTYLE (1054) (1055) (1056) KD (1057) (1058)(1053) SASSSVSSSYL NTSNLAS HQWRSYPPT SGYWN YISYSGSTYYNPSLK SLLWFSTGFAYY (1059) (1060) (1061) (1062) S (1063) (1064) SANSSVSYMH DTSKLASQQWSSNPWT SYGVH YIWSGGITDYNAAFK LGFYAMDY (1065) (1066) (1067) (1051)S (1068) (1048) RASQSVSTSSY YASNLES QNSWEIPYT STGMS SISSGGTTYYLGSVQGYDAGFAY SYMH (1069) (1036) (1070) (1071) G (1072) (1073) KSSQSLLYSSNWASNRES QQYYSYPLT SGYWT YIYTGSTYYNPSLKS QRDWLGFAY QKNSLA (1075) (1076)(1077) (1078) (1079) (1074) RASQSVSTSSY YASNLES QHSWEIPYT SYGMSSISSGGSIYYPDSVK GYDAGFAF SYVH (1080) (1036) (1037) (1038) G (1081)(1082) Group P GFTFSMYMMM (1083) GFTFSAYAMA (1084) GFTFSAYRMF (1085)GFTFSAYLMV (1086) GFTFSAYVMF (1087) GFTFSAYVMS (1088) GFTFSGYLMV (1089)GFTFSGYQML (1090) GFTFSGYSMF (1091) GFTFSGYWMA (1092) GFTFSQYLMY (1093)GFTFSQYVMF (1094) GFTFSQYYMY (1095) GFTFSSYLMS (1096) GFTFSSYLMT (1097)GFTFSSYQMV (1098) GFTFSSYSMA (1099) GFTFSSYVMF (1100) GFTFSSYVMS (1101)GFTFSSYVMY (1102) GFTFSSYYMF (1103) GFTFSSYYMV (1104) GFTFSYYSMV (1105)GFTFSWYLMA (1106) GFTFSWYQMS (1107)

The ABs in the activatable antibodies of the disclosure specificallybind a PDL1 target, such as, for example, mammalian PDL1, and/or humanPDL1. Also included in the disclosure are ABs that bind to the same PDL1epitope as an antibody of the disclosure and/or an activated activatableantibody described herein. Also included in the disclosure are ABs thatcompete with an anti-PDL1 antibody and/or an activated anti-PDL1activatable antibody described herein for binding to a PDL1 target,e.g., human PDL1. Also included in the disclosure are ABs thatcross-compete with an anti-PDL1 antibody and/or an activated anti-PDL1activatable antibody described herein for binding to a PDL1 target,e.g., human PDL1.

The activatable anti-PDL1 antibodies provided herein include a maskingmoiety. In some embodiments, the masking moiety is an amino acidsequence that is coupled or otherwise attached to the anti-PDL1 antibodyand is positioned within the activatable anti-PDL1 antibody constructsuch that the masking moiety reduces the ability of the anti-PDL1antibody to specifically bind PDL1. Suitable masking moieties areidentified using any of a variety of known techniques. For example,peptide masking moieties are identified using the methods described inPCT Publication No. WO 2009/025846 by Daugherty et al., the contents ofwhich are hereby incorporated by reference in their entirety.

The activatable anti-PDL1 antibodies provided herein include a cleavablemoiety. In some embodiments, the cleavable moiety includes an amino acidsequence that is a substrate for a protease, usually an extracellularprotease. Suitable substrates are identified using any of a variety ofknown techniques. For example, peptide substrates are identified usingthe methods described in U.S. Pat. No. 7,666,817 by Daugherty et al.; inU.S. Pat. No. 8,563,269 by Stagliano et al., and in PCT Publication No.WO 2014/026136 by La Porte et al., the contents of each of which arehereby incorporated by reference in their entirety. (See also Boulwareet al. “Evolutionary optimization of peptide substrates for proteasesthat exhibit rapid hydrolysis kinetics.” Biotechnol Bioeng. 106.3(2010): 339-46).

Exemplary substrates include but are not limited to substrates cleavableby one or more of the following enzymes or proteases listed in Table 12.

TABLE 12 Exemplary Proteases and/or Enzymes ADAMS, ADAMTS, e.g. ADAM8ADAM9 ADAM10 ADAM12 ADAM15 ADAM17/TACE ADAMDEC1 ADAMTS1 ADAMTS4 ADAMTS5Aspartate proteases, e.g., BACE Renin Aspartic cathepsins, e.g.,Cathepsin D Cathepsin E Caspases, e.g., Caspase 1 Caspase 2 Caspase 3Caspase 4 Caspase 5 Caspase 6 Caspase 7 Caspase 8 Caspase 9 Caspase 10Caspase 14 Cysteine cathepsins, e.g., Cathepsin B Cathepsin C CathepsinK Cathepsin L Cathepsin S Cathepsin V/L2 Cathepsin X/Z/P Cysteineproteinases, e.g., Cruzipain Legumain Otubain-2 KLKs, e.g., KLK4 KLK5KLK6 KLK7 KLK8 KLK10 KLK11 KLK13 KLK14 Metallo proteinases, e.g., MeprinNeprilysin PSMA BMP-1 MMPs, e.g., MMP1 MMP2 MMP3 MMP7 MMP8 MMP9 MMP10MMP11 MMP12 MMP13 MMP14 MMP15 MMP16 MMP17 MMP19 MMP20 MMP23 MMP24 MMP26MMP27 Serine proteases, e.g., activated protein C Cathepsin A CathepsinG Chymase coagulation factor proteases (e.g., FVIIa, FIXa, FXa, FXIa,FXIIa) Elastase Granzyme B Guanidinobenzoatase HtrA1 Human NeutrophilElastase Lactoferrin Marapsin NS3/4A PACE4 Plasmin PSA tPA ThrombinTryptase uPA Type II Transmembrane Serine Proteases (TTSPs), e.g., DESC1DPP-4 FAP Hepsin Matriptase-2 MT-SP1/Matriptase TMPRSS2 TMPRSS3 TMPRSS4

The activatable anti-PDL1 antibodies described herein overcome alimitation of antibody therapeutics, particularly antibody therapeuticsthat are known to be toxic to at least some degree in vivo.Target-mediated toxicity constitutes a major limitation for thedevelopment of therapeutic antibodies. The activatable anti-PDL1antibodies provided herein are designed to address the toxicityassociated with the inhibition of the target in normal tissues bytraditional therapeutic antibodies. These activatable anti-PDL1antibodies remain masked until proteolytically activated at the site ofdisease. Starting with an anti-PDL1 antibody as a parental therapeuticantibody, the activatable anti-PDL1 antibodies of the invention wereengineered by coupling the antibody to an inhibitory mask through alinker that incorporates a protease substrate.

When the AB is modified with a MM and is in the presence of the target,specific binding of the AB to its target is reduced or inhibited, ascompared to the specific binding of the AB not modified with an MM orthe specific binding of the parental AB to the target.

The K_(d) of the AB modified with a MM towards the target is at least 5,10, 25, 50, 100, 250, 500, 1,000, 2,500, 5,000, 10,000, 50,000, 100,000,500,000, 1,000,000, 5,000,000, 10,000,000, 50,000,000 or greater, orbetween 5-10, 10-100, 10-1,000, 10-10,000, 10-100,000, 10-1,000,000,10-10,000,000, 100-1,000, 100-10,000, 100-100,000, 100-1,000,000,100-10,000,000, 1,000-10,000, 1,000-100,000, 1,000-1,000,000,1000-10,000,000, 10,000-100,000, 10,000-1,000,000, 10,000-10,000,000,100,000-1,000,000, or 100,000-10,000,000 times greater than the K_(d) ofthe AB not modified with an MM or of the parental AB towards the target.Conversely, the binding affinity of the AB modified with a MM towardsthe target is at least 2, 3, 4, 5, 10, 25, 50, 100, 250, 500, 1,000,2,500, 5,000, 10,000, 50,000, 100,000, 500,000, 1,000,000, 5,000,000,10,000,000, 50,000,000 or greater, or between 5-10, 10-100, 10-1,000,10-10,000, 10-100,000, 10-1,000,000, 10-10,000,000, 100-1,000,100-10,000, 100-100,000, 100-1,000,000, 100-10,000,000, 1,000-10,000,1,000-100,000, 1,000-1,000,000, 1000-10,000,000, 10,000-100,000,10,000-1,000,000, 10,000-10,000,000, 100,000-1,000,000, or100,000-10,000,000 times lower than the binding affinity of the AB notmodified with an MM or of the parental AB towards the target.

In some embodiments, the dissociation constant (K_(d)) of the MM towardsthe AB is generally greater than the K_(d) of the AB towards the target.The K_(d) of the MM towards the AB can be at least 5, 10, 25, 50, 100,250, 500, 1,000, 2,500, 5,000, 10,000, 100,000, 1,000,000 or even10,000,000 times greater than the K_(d) of the AB towards the target.Conversely, the binding affinity of the MM towards the AB is generallylower than the binding affinity of the AB towards the target. Thebinding affinity of MM towards the AB can be at least 5, 10, 25, 50,100, 250, 500, 1,000, 2,500, 5,000, 10,000, 100,000, 1,000,000 or even10,000,000 times lower than the binding affinity of the AB towards thetarget.

In some embodiments, the dissociation constant (K_(d)) of the MM towardsthe AB is approximately equal to the K_(d) of the AB towards the target.In some embodiments, the dissociation constant (K_(d)) of the MM towardsthe AB is no more than the dissociation constant of the AB towards thetarget.

In some embodiments, the dissociation constant (K_(d)) of the MM towardsthe AB is less than the dissociation constant of the AB towards thetarget.

In some embodiments, the dissociation constant (K_(d)) of the MM towardsthe AB is greater than the dissociation constant of the AB towards thetarget.

In some embodiments, the MM has a K_(d) for binding to the AB that is nomore than the K_(d) for binding of the AB to the target.

In some embodiments, the MM has a K_(d) for binding to the AB that is noless than the K_(d) for binding of the AB to the target.

In some embodiments, the MM has a K_(d) for binding to the AB that isapproximately equal to the K_(d) for binding of the AB to the target.

In some embodiments, the MM has a K_(d) for binding to the AB that isless than the K_(d) for binding of the AB to the target.

In some embodiments, the MM has a K_(d) for binding to the AB that isgreater than the K_(d) for binding of the AB to the target.

In some embodiments, the MM has a K_(d) for binding to the AB that is nomore than 2, 3, 4, 5, 10, 25, 50, 100, 250, 500, or 1,000 fold greaterthan the K_(d) for binding of the AB to the target. In some embodiments,the MM has a K_(d) for binding to the AB that is between 1-5, 2-5, 2-10,5-10, 5-20, 5-50, 5-100, 10-100, 10-1,000, 20-100, 20-1000, or 100-1,000fold greater than the K_(d) for binding of the AB to the target.

In some embodiments, the MM has an affinity for binding to the AB thatis less than the affinity of binding of the AB to the target.

In some embodiments, the MM has an affinity for binding to the AB thatis no more than the affinity of binding of the AB to the target.

In some embodiments, the MM has an affinity for binding to the AB thatis approximately equal of the affinity of binding of the AB to thetarget.

In some embodiments, the MM has an affinity for binding to the AB thatis no less than the affinity of binding of the AB to the target.

In some embodiments, the MM has an affinity for binding to the AB thatis greater than the affinity of binding of the AB to the target.

In some embodiments, the MM has an affinity for binding to the AB thatis 2, 3, 4, 5, 10, 25, 50, 100, 250, 500, or 1,000 less than theaffinity of binding of the AB to the target. I In some embodiments, theMM has an affinity for binding to the AB that is between 1-5, 2-5, 2-10,5-10, 5-20, 5-50, 5-100, 10-100, 10-1,000, 20-100, 20-1000, or 100-1,000fold less than the affinity of binding of the AB to the target. In someembodiments, the MM has an affinity for binding to the AB that is 2 to20 fold less than the affinity of binding of the AB to the target. Insome embodiments, a MM not covalently linked to the AB and at equimolarconcentration to the AB does not inhibit the binding of the AB to thetarget.

When the AB is modified with a MM and is in the presence of the targetspecific binding of the AB to its target is reduced or inhibited, ascompared to the specific binding of the AB not modified with an MM orthe specific binding of the parental AB to the target. When compared tothe binding of the AB not modified with an MM or the binding of theparental AB to the target the AB's ability to bind the target whenmodified with an MM can be reduced by at least 50%, 60%, 70%, 80%, 90%,92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% and even 100% for at least 2, 4,6, 8, 12, 28, 24, 30, 36, 48, 60, 72, 84, or 96 hours, or 5, 10, 15, 30,45, 60, 90, 120, 150, or 180 days, or 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,or 12 months or more when measured in vivo or in an in vitro assay.

The MM inhibits the binding of the AB to the target. The MM binds theantigen binding domain of the AB and inhibits binding of the AB to thetarget. The MM can sterically inhibit the binding of the AB to thetarget. The MM can allosterically inhibit the binding of the AB to itstarget. In these embodiments when the AB is modified or coupled to a MMand in the presence of target there is no binding or substantially nobinding of the AB to the target, or no more than 0.001%, 0.01%, 0.1%,1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%,or 50% binding of the AB to the target, as compared to the binding ofthe AB not modified with an MM, the parental AB, or the AB not coupledto an MM to the target, for at least 2, 4, 6, 8, 12, 28, 24, 30, 36, 48,60, 72, 84, or 96 hours, or 5, 10, 15, 30, 45, 60, 90, 120, 150, or 180days, or 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 months or longer whenmeasured in vivo or in an in vitro assay.

When an AB is coupled to or modified by a MM, the MM ‘masks’ or reducesor otherwise inhibits the specific binding of the AB to the target. Whenan AB is coupled to or modified by a MM, such coupling or modificationcan effect a structural change that reduces or inhibits the ability ofthe AB to specifically bind its target.

An AB coupled to or modified with an MM can be represented by thefollowing formulae (in order from an amino (N) terminal region tocarboxyl (C) terminal region:

(MM)-(AB)

(AB)-(MM)

(MM)-L-(AB)

(AB)-L-(MM)

where MM is a masking moiety, the AB is an antibody or antibody fragmentthereof, and the L is a linker. In many embodiments, it may be desirableto insert one or more linkers, e.g., flexible linkers, into thecomposition so as to provide for flexibility.

In certain embodiments, the MM is not a natural binding partner of theAB. In some embodiments, the MM contains no or substantially no homologyto any natural binding partner of the AB. In some embodiments, the MM isno more than 5%, 10%, 15%, 20%, 25%, 300, 35%, 40%, 45%, 50%, 55%, 60%,65%, 70%, 75%, or 80% similar to any natural binding partner of the AB.In some embodiments, the MM is no more than 5%, 10%, 15%, 20%, 25%, 30%,35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80% identical to anynatural binding partner of the AB. In some embodiments, the MM is nomore than 25% identical to any natural binding partner of the AB. Insome embodiments, the MM is no more than 50% identical to any naturalbinding partner of the AB. In some embodiments, the MM is no more than20% identical to any natural binding partner of the AB. In someembodiments, the MM is no more than 10% identical to any natural bindingpartner of the AB.

In some embodiments, the activatable antibodies include an AB that ismodified by an MM and also includes one or more cleavable moieties (CM).Such activatable antibodies exhibit activatable/switchable binding, tothe AB's target. Activatable antibodies generally include an antibody orantibody fragment (AB), modified by or coupled to a masking moiety (MM)and a modifiable or cleavable moiety (CM). In some embodiments, the CMcontains an amino acid sequence that serves as a substrate for at leastone protease.

The elements of the activatable antibodies are arranged so that the MMand CM are positioned such that in a cleaved (or relatively active)state and in the presence of a target, the AB binds a target while theactivatable antibody is in an uncleaved (or relatively inactive) statein the presence of the target, specific binding of the AB to its targetis reduced or inhibited. The specific binding of the AB to its targetcan be reduced due to the inhibition or masking of the AB's ability tospecifically bind its target by the MM.

The K_(d) of the AB modified with a MM and a CM towards the target is atleast 5, 10, 25, 50, 100, 250, 500, 1,000, 2,500, 5,000, 10,000, 50,000,100,000, 500,000, 1,000,000, 5,000,000, 10,000,000, 50,000,000 orgreater, or between 5-10, 10-100, 10-1,000, 10-10,000, 10-100,000,10-1,000,000, 10-10,000,000, 100-1,000, 100-10,000, 100-100,000,100-1,000,000, 100-10,000,000, 1,000-10,000, 1,000-100,000,1,000-1,000,000, 1000-10,000,000, 10,000-100,000, 10,000-1,000,000,10,000-10,000,000, 100,000-1,000,000, or 100,000-10,000,000 timesgreater than the K_(d) of the AB not modified with an MM and a CM or ofthe parental AB towards the target. Conversely, the binding affinity ofthe AB modified with a MM and a CM towards the target is at least 5, 10,25, 50, 100, 250, 500, 1,000, 2,500, 5,000, 10,000, 50,000, 100,000,500,000, 1,000,000, 5,000,000, 10,000,000, 50,000,000 or greater, orbetween 5-10, 10-100, 10-1,000, 10-10,000, 10-100,000, 10-1,000,000,10-10,000,000, 100-1,000, 100-10,000, 100-100,000, 100-1,000,000,100-10,000,000, 1,000-10,000, 1,000-100,000, 1,000-1,000,000,1000-10,000,000, 10,000-100,000, 10,000-1,000,000, 10,000-10,000,000,100,000-1,000,000, or 100,000-10,000,000 times lower than the bindingaffinity of the AB not modified with an MM and a CM or of the parentalAB towards the target.

When the AB is modified with a MM and a CM and is in the presence of thetarget but not in the presence of a modifying agent (for example atleast one protease), specific binding of the AB to its target is reducedor inhibited, as compared to the specific binding of the AB not modifiedwith an MM and a CM or of the parental AB to the target. When comparedto the binding of the parental AB or the binding of an AB not modifiedwith an MM and a CM to its target, the AB's ability to bind the targetwhen modified with an MM and a CM can be reduced by at least 50%, 60%,70%, 80%, 90%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% and even 100% forat least 2, 4, 6, 8, 12, 28, 24, 30, 36, 48, 60, 72, 84, or 96 hours or5, 10, 15, 30, 45, 60, 90, 120, 150, or 180 days, or 1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, or 12 months or longer when measured in vivo or in anin vitro assay.

As used herein, the term cleaved state refers to the condition of theactivatable antibodies following modification of the CM by at least oneprotease. The term uncleaved state, as used herein, refers to thecondition of the activatable antibodies in the absence of cleavage ofthe CM by a protease. As discussed above, the term “activatableantibodies” is used herein to refer to an activatable antibody in bothits uncleaved (native) state, as well as in its cleaved state. It willbe apparent to the ordinarily skilled artisan that in some embodiments acleaved activatable antibody may lack an MM due to cleavage of the CM byprotease, resulting in release of at least the MM (e.g., where the MM isnot joined to the activatable antibodies by a covalent bond (e.g., adisulfide bond between cysteine residues).

By activatable or switchable is meant that the activatable antibodyexhibits a first level of binding to a target when the activatableantibody is in a inhibited, masked or uncleaved state (i.e., a firstconformation), and a second level of binding to the target in theuninhibited, unmasked and/or cleaved state (i.e., a secondconformation), where the second level of target binding is greater thanthe first level of binding. In general, the access of target to the ABof the activatable antibody is greater in the presence of a cleavingagent capable of cleaving the CM, i.e., a protease, than in the absenceof such a cleaving agent. Thus, when the activatable antibody is in theuncleaved state, the AB is inhibited from target binding and can bemasked from target binding (i.e., the first conformation is such the ABcannot bind the target), and in the cleaved state the AB is notinhibited or is unmasked to target binding.

The CM and AB of the activatable antibodies are selected so that the ABrepresents a binding moiety for a given target, and the CM represents asubstrate for a protease. In some embodiments, the protease isco-localized with the target at a treatment site or diagnostic site in asubject. As used herein, co-localized refers to being at the same siteor relatively close nearby. In some embodiments, a protease cleaves a CMyielding an activated antibody that binds to a target located nearby thecleavage site. The activatable antibodies disclosed herein findparticular use where, for example, a protease capable of cleaving a sitein the CM, i.e., a protease, is present at relatively higher levels inor in close proximity to target-containing tissue of a treatment site ordiagnostic site than in tissue of non-treatment sites (for example inhealthy tissue). In some embodiments, a CM of the disclosure is alsocleaved by one or more other proteases. In some embodiments, it is theone or more other proteases that is co-localized with the target andthat is responsible for cleavage of the CM in vivo.

In some embodiments activatable antibodies provide for reduced toxicityand/or adverse side effects that could otherwise result from binding ofthe AB at non-treatment sites if the AB were not masked or otherwiseinhibited from binding to the target.

In general, an activatable antibody can be designed by selecting an ABof interest and constructing the remainder of the activatable antibodyso that, when conformationally constrained, the MM provides for maskingof the AB or reduction of binding of the AB to its target. Structuraldesign criteria can be to be taken into account to provide for thisfunctional feature.

Activatable antibodies exhibiting a switchable phenotype of a desireddynamic range for target binding in an inhibited versus an uninhibitedconformation are provided. Dynamic range generally refers to a ratio of(a) a maximum detected level of a parameter under a first set ofconditions to (b) a minimum detected value of that parameter under asecond set of conditions. For example, in the context of an activatableantibody, the dynamic range refers to the ratio of (a) a maximumdetected level of target protein binding to an activatable antibody inthe presence of at least one protease capable of cleaving the CM of theactivatable antibodies to (b) a minimum detected level of target proteinbinding to an activatable antibody in the absence of the protease. Thedynamic range of an activatable antibody can be calculated as the ratioof the dissociation constant of an activatable antibody cleaving agent(e.g., enzyme) treatment to the dissociation constant of the activatableantibodies cleaving agent treatment. The greater the dynamic range of anactivatable antibody, the better the switchable phenotype of theactivatable antibody. Activatable antibodies having relatively higherdynamic range values (e.g., greater than 1) exhibit more desirableswitching phenotypes such that target protein binding by the activatableantibodies occurs to a greater extent (e.g., predominantly occurs) inthe presence of a cleaving agent (e.g., enzyme) capable of cleaving theCM of the activatable antibodies than in the absence of a cleavingagent.

Activatable antibodies can be provided in a variety of structuralconfigurations. Exemplary formulae for activatable antibodies areprovided below. It is specifically contemplated that the N- toC-terminal order of the AB, MM and CM may be reversed within anactivatable antibody. It is also specifically contemplated that the CMand MM may overlap in amino acid sequence, e.g., such that the CM iscontained within the MM.

For example, activatable antibodies can be represented by the followingformula (in order from an amino (N) terminal region to carboxyl (C)terminal region:

(MM)-(CM)-(AB)

(AB)-(CM)-(MM)

where MM is a masking moiety, CM is a cleavable moiety, and AB is anantibody or fragment thereof. It should be noted that although MM and CMare indicated as distinct components in the formulae above, in allexemplary embodiments (including formulae) disclosed herein it iscontemplated that the amino acid sequences of the MM and the CM couldoverlap, e.g., such that the CM is completely or partially containedwithin the MM. In addition, the formulae above provide for additionalamino acid sequences that may be positioned N-terminal or C-terminal tothe activatable antibodies elements.

In certain embodiments, the MM is not a natural binding partner of theAB. In some embodiments, the MM contains no or substantially no homologyto any natural binding partner of the AB. In some embodiments, the MM isno more than 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%,65%, 70%, 75%, or 80% similar to any natural binding partner of the AB.In some embodiments, the MM is no more than 5%, 10%, 15%, 20%, 25%, 30%,35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80% identical to anynatural binding partner of the AB. In some embodiments, the MM is nomore than 50% identical to any natural binding partner of the AB. Insome embodiments, the MM is no more than 25% identical to any naturalbinding partner of the AB. In some embodiments, the MM is no more than20% identical to any natural binding partner of the AB. In someembodiments, the MM is no more than 10% identical to any natural bindingpartner of the AB.

In many embodiments it may be desirable to insert one or more linkers,e.g., flexible linkers, into the activatable antibody construct so as toprovide for flexibility at one or more of the MM-CM junction, the CM-ABjunction, or both. For example, the AB, MM, and/or CM may not contain asufficient number of residues (e.g., Gly, Ser, Asp, Asn, especially Glyand Ser, particularly Gly) to provide the desired flexibility. As such,the switchable phenotype of such activatable antibody constructs maybenefit from introduction of one or more amino acids to provide for aflexible linker. In addition, as described below, where the activatableantibody is provided as a conformationally constrained construct, aflexible linker can be operably inserted to facilitate formation andmaintenance of a cyclic structure in the uncleaved activatable antibody.

For example, in certain embodiments an activatable antibody comprisesone of the following formulae (where the formula below represent anamino acid sequence in either N- to C-terminal direction or C- toN-terminal direction):

(MM)-L1-(CM)-(AB)

(MM)-(CM)-L2-(AB)

(MM)-L1-(CM)-L2-(AB)

wherein MM, CM, and AB are as defined above; wherein L1 and L2 are eachindependently and optionally present or absent, are the same ordifferent flexible linkers that include at least 1 flexible amino acid(e.g., Gly). In addition, the formulae above provide for additionalamino acid sequences that may be positioned N-terminal or C-terminal tothe activatable antibodies elements. Examples include, but are notlimited to, targeting moieties (e.g., a ligand for a receptor of a cellpresent in a target tissue) and serum half-life extending moieties(e.g., polypeptides that bind serum proteins, such as immunoglobulin(e.g., IgG) or serum albumin (e.g., human serum albumin (HAS)).

The CM is specifically cleaved by at least one protease at a rate ofabout 0.001-1500×10⁴ M⁻¹S⁻¹ or at least 0.001, 0.005, 0.01, 0.05, 0.1,0.5, 1, 2.5, 5, 7.5, 10, 15, 20, 25, 50, 75, 100, 125, 150, 200, 250,500, 750, 1000, 1250, or 1500×10⁴ M⁻¹S⁻¹. In some embodiments, the CM isspecifically cleaved at a rate of about 100,000 M⁻¹S⁻¹. In someembodiments, the CM is specifically cleaved at a rate from about 1×10E2to about 1×10E6 M⁻¹S⁻¹ (i.e., from about 1×10² to about 1×10⁶ M⁻¹S⁻¹).

For specific cleavage by an enzyme, contact between the enzyme and CM ismade. When the activatable antibody comprising an AB coupled to a MM anda CM is in the presence of target and sufficient enzyme activity, the CMcan be cleaved. Sufficient enzyme activity can refer to the ability ofthe enzyme to make contact with the CM and effect cleavage. It canreadily be envisioned that an enzyme may be in the vicinity of the CMbut unable to cleave because of other cellular factors or proteinmodification of the enzyme.

Linkers suitable for use in compositions described herein are generallyones that provide flexibility of the modified AB or the activatableantibodies to facilitate the inhibition of the binding of the AB to thetarget. Such linkers are generally referred to as flexible linkers.Suitable linkers can be readily selected and can be of any of a suitableof different lengths, such as from 1 amino acid (e.g., Gly) to 20 aminoacids, from 2 amino acids to 15 amino acids, from 3 amino acids to 12amino acids, including 4 amino acids to 10 amino acids, 5 amino acids to9 amino acids, 6 amino acids to 8 amino acids, or 7 amino acids to 8amino acids, and may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19, or 20 amino acids in length.

Exemplary flexible linkers include glycine polymers (G)n, glycine-serinepolymers (including, for example, (GS)n, (GSGGS)n (SEQ ID NO: 191) and(GGGS)n (SEQ ID NO: 192), where n is an integer of at least one),glycine-alanine polymers, alanine-serine polymers, and other flexiblelinkers known in the art. Glycine and glycine-serine polymers arerelatively unstructured, and therefore may be able to serve as a neutraltether between components. Glycine accesses significantly more phi-psispace than even alanine, and is much less restricted than residues withlonger side chains (see Scheraga, Rev. Computational Chem. 11173-142(1992)). Exemplary flexible linkers include, but are not limited toGly-Gly-Ser-Gly (SEQ ID NO: 193), Gly-Gly-Ser-Gly-Gly (SEQ ID NO: 194),Gly-Ser-Gly-Ser-Gly (SEQ ID NO: 195), Gly-Ser-Gly-Gly-Gly (SEQ ID NO:196), Gly-Gly-Gly-Ser-Gly (SEQ ID NO: 197), Gly-Ser-Ser-Ser-Gly (SEQ IDNO: 198), and the like. The ordinarily skilled artisan will recognizethat design of an activatable antibodies can include linkers that areall or partially flexible, such that the linker can include a flexiblelinker as well as one or more portions that confer less flexiblestructure to provide for a desired activatable antibodies structure.

The disclosure also provides compositions and methods that include anactivatable anti-PDL1 antibody that includes an antibody or antibodyfragment (AB) that specifically binds PDL1, where the AB is coupled to amasking moiety (MM) that decreases the ability of the AB to bind itstarget. In some embodiments, the activatable anti-PDL1 antibody furtherincludes a cleavable moiety (CM) that is a substrate for a protease. Thecompositions and methods provided herein enable the attachment of one ormore agents to one or more cysteine residues in the AB withoutcompromising the activity (e.g., the masking, activating or bindingactivity) of the activatable anti-PDL1 antibody. In some embodiments,the compositions and methods provided herein enable the attachment ofone or more agents to one or more cysteine residues in the AB withoutreducing or otherwise disturbing one or more disulfide bonds within theMM. The compositions and methods provided herein produce an activatableanti-PDL1 antibody that is conjugated to one or more agents, e.g., anyof a variety of therapeutic, diagnostic and/or prophylactic agents, forexample, in some embodiments, without any of the agent(s) beingconjugated to the MM of the activatable anti-PDL1 antibody. Thecompositions and methods provided herein produce conjugated activatableanti-PDL1 antibodies in which the MM retains the ability to effectivelyand efficiently mask the AB of the activatable antibody in an uncleavedstate. The compositions and methods provided herein produce conjugatedactivatable anti-PDL1 antibodies in which the activatable antibody isstill activated, i.e., cleaved, in the presence of a protease that cancleave the CM.

The activatable anti-PDL1 antibodies have at least one point ofconjugation for an agent, but in the methods and compositions providedherein less than all possible points of conjugation are available forconjugation to an agent. In some embodiments, the one or more points ofconjugation are sulfur atoms involved in disulfide bonds. In someembodiments, the one or more points of conjugation are sulfur atomsinvolved in interchain disulfide bonds. In some embodiments, the one ormore points of conjugation are sulfur atoms involved in interchainsulfide bonds, but not sulfur atoms involved in intrachain disulfidebonds. In some embodiments, the one or more points of conjugation aresulfur atoms of cysteine or other amino acid residues containing asulfur atom. Such residues may occur naturally in the antibody structureor may be incorporated into the antibody by site-directed mutagenesis,chemical conversion, or mis-incorporation of non-natural amino acids.

Also provided are methods of preparing a conjugate of an activatableanti-PDL1 antibody having one or more interchain disulfide bonds in theAB and one or more intrachain disulfide bonds in the MM, and a drugreactive with free thiols is provided. The method generally includespartially reducing interchain disulfide bonds in the activatableantibody with a reducing agent, such as, for example, TCEP; andconjugating the drug reactive with free thiols to the partially reducedactivatable antibody. As used herein, the term partial reduction refersto situations where an activatable anti-PDL1 antibody is contacted witha reducing agent and less than all disulfide bonds, e.g., less than allpossible sites of conjugation are reduced. In some embodiments, lessthan 99%, 98%, 97%, 96%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%,50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10% or less than 5% of allpossible sites of conjugation are reduced.

In yet other embodiments, a method of reducing and conjugating an agent,e.g., a drug, to an activatable anti-PDL1 antibody resulting inselectivity in the placement of the agent is provided. The methodgenerally includes partially reducing the activatable anti-PDL1 antibodywith a reducing agent such that any conjugation sites in the maskingmoiety or other non-AB portion of the activatable antibody are notreduced, and conjugating the agent to interchain thiols in the AB. Theconjugation site(s) are selected so as to allow desired placement of anagent to allow conjugation to occur at a desired site. The reducingagent is, for example, TCEP. The reduction reaction conditions such as,for example, the ratio of reducing agent to activatable antibody, thelength of incubation, the temperature during the incubation, the pH ofthe reducing reaction solution, etc., are determined by identifying theconditions that produce a conjugated activatable antibody in which theMM retains the ability to effectively and efficiently mask the AB of theactivatable antibody in an uncleaved state. The ratio of reduction agentto activatable anti-PDL1 antibody will vary depending on the activatableantibody. In some embodiments, the ratio of reducing agent toactivatable anti-PDL1 antibody will be in a range from about 20:1 to1:1, from about 10:1 to 1:1, from about 9:1 to 1:1, from about 8:1 to1:1, from about 7:1 to 1:1, from about 6:1 to 1:1, from about 5:1 to1:1, from about 4:1 to 1:1, from about 3:1 to 1:1, from about 2:1 to1:1, from about 20:1 to 1:1.5, from about 10:1 to 1:1.5, from about 9:1to 1:1.5, from about 8:1 to 1:1.5, from about 7:1 to 1:1.5, from about6:1 to 1:1.5, from about 5:1 to 1:1.5, from about 4:1 to 1:1.5, fromabout 3:1 to 1:1.5, from about 2:1 to 1:1.5, from about 1.5:1 to 1:1.5,or from about 1:1 to 1:1.5. In some embodiments, the ratio is in a rangeof from about 5:1 to 1:1. In some embodiments, the ratio is in a rangeof from about 5:1 to 1.5:1. In some embodiments, the ratio is in a rangeof from about 4:1 to 1:1. In some embodiments, the ratio is in a rangefrom about 4:1 to 1.5:1. In some embodiments, the ratio is in a rangefrom about 8:1 to about 1:1. In some embodiments, the ratio is in arange of from about 2.5:1 to 1:1.

In some embodiments, a method of reducing interchain disulfide bonds inthe AB of an activatable anti-PDL1 antibody and conjugating an agent,e.g., a thiol-containing agent such as a drug, to the resultinginterchain thiols to selectively locate agent(s) on the AB is provided.The method generally includes partially reducing the AB with a reducingagent to form at least two interchain thiols without forming allpossible interchain thiols in the activatable antibody; and conjugatingthe agent to the interchain thiols of the partially reduced AB. Forexample, the AB of the activatable antibody is partially reduced forabout 1 hour at about 37° C. at a desired ratio of reducingagent:activatable antibody. In some embodiments, the ratio of reducingagent to activatable antibody will be in a range from about 20:1 to 1:1,from about 10:1 to 1:1, from about 9:1 to 1:1, from about 8:1 to 1:1,from about 7:1 to 1:1, from about 6:1 to 1:1, from about 5:1 to 1:1,from about 4:1 to 1:1, from about 3:1 to 1:1, from about 2:1 to 1:1,from about 20:1 to 1:1.5, from about 10:1 to 1:1.5, from about 9:1 to1:1.5, from about 8:1 to 1:1.5, from about 7:1 to 1:1.5, from about 6:1to 1:1.5, from about 5:1 to 1:1.5, from about 4:1 to 1:1.5, from about3:1 to 1:1.5, from about 2:1 to 1:1.5, from about 1.5:1 to 1:1.5, orfrom about 1:1 to 1:1.5. In some embodiments, the ratio is in a range offrom about 5:1 to 1:1. In some embodiments, the ratio is in a range offrom about 5:1 to 1.5:1. In some embodiments, the ratio is in a range offrom about 4:1 to 1:1. In some embodiments, the ratio is in a range fromabout 4:1 to 1.5:1. In some embodiments, the ratio is in a range fromabout 8:1 to about 1:1. In some embodiments, the ratio is in a range offrom about 2.5:1 to 1:1.

The thiol-containing reagent can be, for example, cysteine or N-acetylcysteine. The reducing agent can be, for example, TCEP. In someembodiments, the reduced activatable antibody can be purified prior toconjugation, using for example, column chromatography, dialysis, ordiafiltration. Alternatively, the reduced antibody is not purified afterpartial reduction and prior to conjugation.

The invention also provides partially reduced activatable anti-PDL1antibodies in which at least one interchain disulfide bond in theactivatable antibody has been reduced with a reducing agent withoutdisturbing any intrachain disulfide bonds in the activatable antibody,wherein the activatable antibody includes an antibody or an antigenbinding fragment thereof (AB) that specifically binds to PDL1, a maskingmoiety (MM) that inhibits the binding of the AB of the activatableantibody in an uncleaved state to the PDL1 target, and a cleavablemoiety (CM) coupled to the AB, wherein the CM is a polypeptide thatfunctions as a substrate for a protease. In some embodiments the MM iscoupled to the AB via the CM. In some embodiments, one or moreintrachain disulfide bond(s) of the activatable antibody is notdisturbed by the reducing agent. In some embodiments, one or moreintrachain disulfide bond(s) of the MM within the activatable antibodyis not disturbed by the reducing agent. In some embodiments, theactivatable antibody in the uncleaved state has the structuralarrangement from N-terminus to C-terminus as follows: MM-CM-AB orAB-CM-MM. In some embodiments, reducing agent is TCEP.

The disclosure also provides partially reduced activatable antibodies inwhich at least one interchain disulfide bond in the activatable antibodyhas been reduced with a reducing agent without disturbing any intrachaindisulfide bonds in the activatable antibody, wherein the activatableantibody includes an antibody or an antigen binding fragment thereof(AB) that specifically binds to the target, e.g., PDL1, a masking moiety(MM) that inhibits the binding of the AB of the activatable antibody inan uncleaved state to the target, and a cleavable moiety (CM) coupled tothe AB, wherein the CM is a polypeptide that functions as a substratefor at least one protease. In some embodiments, the MM is coupled to theAB via the CM. In some embodiments, one or more intrachain disulfidebond(s) of the activatable antibody is not disturbed by the reducingagent. In some embodiments, one or more intrachain disulfide bond(s) ofthe MM within the activatable antibody is not disturbed by the reducingagent. In some embodiments, the activatable antibody in the uncleavedstate has the structural arrangement from N-terminus to C-terminus asfollows: MM-CM-AB or AB-CM-MM. In some embodiments, reducing agent isTCEP.

In some embodiments, the activatable antibodies described herein alsoinclude an agent conjugated to the activatable antibody. In someembodiments, the conjugated agent is a therapeutic agent, such as ananti-inflammatory and/or an antineoplastic agent. In such embodiments,the agent is conjugated to a carbohydrate moiety of the activatableantibody, for example, in some embodiments, where the carbohydratemoiety is located outside the antigen-binding region of the antibody orantigen-binding fragment in the activatable antibody. In someembodiments, the agent is conjugated to a sulfhydryl group of theantibody or antigen-binding fragment in the activatable antibody.

In some embodiments, the agent is a cytotoxic agent such as a toxin(e.g., an enzymatically active toxin of bacterial, fungal, plant, oranimal origin, or fragments thereof), or a radioactive isotope (i.e., aradioconjugate).

In some embodiments, the agent is a detectable moiety such as, forexample, a label or other marker. For example, the agent is or includesa radiolabeled amino acid, one or more biotinyl moieties that can bedetected by marked avidin (e.g., streptavidin containing a fluorescentmarker or enzymatic activity that can be detected by optical orcalorimetric methods), one or more radioisotopes or radionuclides, oneor more fluorescent labels, one or more enzymatic labels, and/or one ormore chemiluminescent agents. In some embodiments, detectable moietiesare attached by spacer molecules.

The disclosure also pertains to immunoconjugates comprising an antibodyconjugated to a cytotoxic agent such as a toxin (e.g., an enzymaticallyactive toxin of bacterial, fungal, plant, or animal origin, or fragmentsthereof), or a radioactive isotope (i.e., a radioconjugate). Suitablecytotoxic agents include, for example, dolastatins and derivativesthereof (e.g. auristatin E, AFP, MMAF, MMAE, MMAD, DMAF, DMAE). Forexample, the agent is monomethyl auristatin E (MMAE) or monomethylauristatin D (MMAD). In some embodiments, the agent is an agent selectedfrom the group listed in Table 11. In some embodiments, the agent is adolastatin. In some embodiments, the agent is an auristatin orderivative thereof. In some embodiments, the agent is auristatin E or aderivative thereof. In some embodiments, the agent is monomethylauristatin E (MMAE). In some embodiments, the agent is monomethylauristatin D (MMAD). In some embodiments, the agent is a maytansinoid ormaytansinoid derivative. In some embodiments, the agent is DM1 or DM4.In some embodiments, the agent is a duocarmycin or derivative thereof.In some embodiments, the agent is a calicheamicin or derivative thereof.In some embodiments, the agent is a pyrrolobenzodiazepine. In someembodiments, the agent is a pyrrolobenzodiazepine dimer.

In some embodiments, the agent is linked to the AB using a maleimidecaproyl-valine-citrulline linker or a maleimide PEG-valine-citrullinelinker. In some embodiments, the agent is linked to the AB using amaleimide caproyl-valine-citrulline linker. In some embodiments, theagent is linked to the AB using a maleimide PEG-valine-citrulline linkerIn some embodiments, the agent is monomethyl auristatin D (MMAD) linkedto the AB using a maleimidePEG-valine-citrulline-para-aminobenzyloxycarbonyl linker, and thislinker payload construct is referred to herein as “vc-MMAD.” In someembodiments, the agent is monomethyl auristatin E (MMAE) linked to theAB using a maleimide PEG-valine-citrulline-para-aminobenzyloxycarbonyllinker, and this linker payload construct is referred to herein as“vc-MMAE.” The structures of vc-MMAD and vc-MMAE are shown below:

The disclosure also provides conjugated activatable antibodies thatinclude an activatable antibody linked to monomethyl auristatin D (MMAD)payload, wherein the activatable antibody includes an antibody or anantigen binding fragment thereof (AB) that specifically binds to atarget, a masking moiety (MM) that inhibits the binding of the AB of theactivatable antibody in an uncleaved state to the target, and cleavablemoiety (CM) coupled to the AB, and the CM is a polypeptide thatfunctions as a substrate for at least one MMP protease.

In some embodiments, the MMAD-conjugated activatable antibody can beconjugated using any of several methods for attaching agents to ABs: (a)attachment to the carbohydrate moieties of the AB, or (b) attachment tosulfhydryl groups of the AB, or (c) attachment to amino groups of theAB, or (d) attachment to carboxylate groups of the AB.

In some embodiments, the MMAD payload is conjugated to the AB via alinker. In some embodiments, the MMAD payload is conjugated to acysteine in the AB via a linker. In some embodiments, the MMAD payloadis conjugated to a lysine in the AB via a linker. In some embodiments,the MMAD payload is conjugated to another residue of the AB via alinker, such as those residues disclosed herein. In some embodiments,the linker is a thiol-containing linker. In some embodiments, the linkeris a cleavable linker. In some embodiments, the linker is anon-cleavable linker. In some embodiments, the linker is selected fromthe group consisting of the linkers shown in Tables 13 and 14. In someembodiments, the activatable antibody and the MMAD payload are linkedvia a maleimide caproyl-valine-citrulline linker. In some embodiments,the activatable antibody and the MMAD payload are linked via a maleimidePEG-valine-citrulline linker. In some embodiments, the activatableantibody and the MMAD payload are linked via a maleimidecaproyl-valine-citrulline-para-aminobenzyloxycarbonyl linker. In someembodiments, the activatable antibody and the MMAD payload are linkedvia a maleimide PEG-valine-citrulline-para-aminobenzyloxycarbonyllinker. In some embodiments, the MMAD payload is conjugated to the ABusing the partial reduction and conjugation technology disclosed herein.

In some embodiments, the polyethylene glycol (PEG) component of a linkerof the present disclosure is formed from 2 ethylene glycol monomers, 3ethylene glycol monomers, 4 ethylene glycol monomers, 5 ethylene glycolmonomers, 6 ethylene glycol monomers, 7 ethylene glycol monomers 8ethylene glycol monomers, 9 ethylene glycol monomers, or at least 10ethylene glycol monomers. In some embodiments of the present disclosure,the PEG component is a branched polymer. In some embodiments of thepresent disclosure, the PEG component is an unbranched polymer. In someembodiments, the PEG polymer component is functionalized with an aminogroup or derivative thereof, a carboxyl group or derivative thereof, orboth an amino group or derivative thereof and a carboxyl group orderivative thereof.

In some embodiments, the PEG component of a linker of the presentdisclosure is an amino-tetra-ethylene glycol-carboxyl group orderivative thereof. In some embodiments, the PEG component of a linkerof the present disclosure is an amino-tri-ethylene glycol-carboxyl groupor derivative thereof. In some embodiments, the PEG component of alinker of the present disclosure is an amino-di-ethylene glycol-carboxylgroup or derivative thereof. In some embodiments, an amino derivative isthe formation of an amide bond between the amino group and a carboxylgroup to which it is conjugated. In some embodiments, a carboxylderivative is the formation of an amide bond between the carboxyl groupand an amino group to which it is conjugated. In some embodiments, acarboxyl derivative is the formation of an ester bond between thecarboxyl group and an hydroxyl group to which it is conjugated.

Enzymatically active toxins and fragments thereof that can be usedinclude diphtheria A chain, nonbinding active fragments of diphtheriatoxin, exotoxin A chain (from Pseudomonas aeruginosa), ricin A chain,abrin A chain, modeccin A chain, alpha-sarcin, Aleurites fordiiproteins, dianthin proteins, Phytolaca americana proteins (PAPI, PAPII,and PAP-S), momordica charantia inhibitor, curcin, crotin, sapaonariaofficinalis inhibitor, gelonin, mitogellin, restrictocin, phenomycin,enomycin, and the tricothecenes. A variety of radionuclides areavailable for the production of radioconjugated antibodies. Examplesinclude ²¹²Bi, ¹³¹I, ¹³¹In, ⁹⁰Y, and ¹⁸⁶Re.

Conjugates of the antibody and cytotoxic agent are made using a varietyof bifunctional protein-coupling agents such asN-succinimidyl-3-(2-pyridyldithiol) propionate (SPDP), iminothiolane(IT), bifunctional derivatives of imidoesters (such as dimethyladipimidate HCL), active esters (such as disuccinimidyl suberate),aldehydes (such as glutareldehyde), bis-azido compounds (such as bis(p-azidobenzoyl) hexanediamine), bis-diazonium derivatives (such asbis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such astolyene 2,6-diisocyanate), and bis-active fluorine compounds (such as1,5-difluoro-2,4-dinitrobenzene). For example, a ricin immunotoxin canbe prepared as described in Vitetta et al., Science 238. 1098 (1987).Carbon-14-labeled 1-isothiocyanatobenzyl-3-methyldiethylenetriaminepentaacetic acid (MX-DTPA) is an exemplary chelating agent forconjugation of radionucleotide to the antibody. (See WO94/11026).

Table 11 lists some of the exemplary pharmaceutical agents that may beemployed in the herein described disclosure but in no way is meant to bean exhaustive list.

TABLE 11 Exemplary Pharmaceutical Agents for Conjugation CYTOTOXICAGENTS Auristatins Auristatin E Monomethyl auristatin D (MMAD)Monomethyl auristatin E (MMAE) Desmethyl auristatin E (DMAE) AuristatinF Monomethyl auristatin F (MMAF) Desmethyl auristatin F (DMAF)Auristatin derivatives, e.g., amides thereof Auristatin tyramineAuristatin quinoline Dolastatins Dolastatin derivatives Dolastatin 16DmJ Dolastatin 16 Dpv Maytansinoids, e.g. DM-1; DM-4 Maytansinoidderivatives Duocarmycin Duocarmycin derivatives Alpha-amanitinAnthracyclines Doxorubicin Daunorubicin Bryostatins CamptothecinCamptothecin derivatives 7-substituted Camptothecin10,11-Difluoromethylenedioxycamptothecin CombretastatinsDebromoaplysiatoxin Kahalalide-F Discodermolide EcteinascidinsANTIVIRALS Acyclovir Vira A Symmetrel ANTIFUNGALS Nystatin ADDITIONALANTI-NEOPLASTICS Adriamycin Cerubidine Bleomycin Alkeran Velban OncovinFluorouracil Methotrexate Thiotepa Bisantrene Novantrone ThioguanineProcarabizine Cytarabine ANTI-BACTERIALS Aminoglycosides StreptomycinNeomycin Kanamycin Amikacin Gentamicin Tobramycin Streptomycin BSpectinomycin Ampicillin Sulfanilamide Polymyxin ChloramphenicolTurbostatin Phenstatins Hydroxyphenstatin Spongistatin 5 Spongistatin 7Halistatin 1 Halistatin 2 Halistatin 3 Modified BryostatinsHalocomstatins Pyrrolobenzimidazoles (PBI) Cibrostatin6 DoxaliformAnthracyclins analogues Cemadotin analogue (CemCH2-SH) Pseudomonas toxinA (PE38) variant Pseudomonas toxin A (ZZ-PE38) variant ZJ-101 OSW-14-Nitrobenzyloxycarbonyl Derivatives of O6-Benzylguanine Topoisomeraseinhibitors Hemiasterlin Cephalotaxine HomoharringtoninePyrrolobenzodiazepine dimers (PBDs) PyrrolobenzodiazepenesFunctionalized pyrrolobenzodiazepenes Functionalizedpyrrolobenzodiazepene dimers Calicheamicins Podophyllotoxins TaxanesVinca alkaloids CONJUGATABLE DETECTION REAGENTS Fluorescein andderivatives thereof Fluorescein isothiocyanate (FITC)RADIOPHARMACEUTICALS ¹²⁵I ¹³¹I ⁸⁹Zr ¹¹¹In ¹²³I ¹³¹I ⁹⁹mTc ²⁰¹Tl ^(l33)Xe¹¹C ⁶²Cu ¹⁸F ⁶⁸Ga ¹³N ¹⁵O ³⁸K ⁸²Rb ⁹⁹mTc (Technetium) HEAVY METALSBarium Gold Platinum ANTI-MYCOPLASMALS Tylosine Spectinomycin

Those of ordinary skill in the art will recognize that a large varietyof possible moieties can be coupled to the resultant antibodies of thedisclosure. (See, for example, “Conjugate Vaccines”, Contributions toMicrobiology and Immunology, J. M. Cruse and R. E. Lewis, Jr (eds),Carger Press, New York, (1989), the entire contents of which areincorporated herein by reference).

Coupling may be accomplished by any chemical reaction that will bind thetwo molecules so long as the antibody and the other moiety retain theirrespective activities. This linkage can include many chemicalmechanisms, for instance covalent binding, affinity binding,intercalation, coordinate binding and complexation. In some embodiments,the binding is, however, covalent binding. Covalent binding can beachieved either by direct condensation of existing side chains or by theincorporation of external bridging molecules. Many bivalent orpolyvalent linking agents are useful in coupling protein molecules, suchas the antibodies of the present disclosure, to other molecules. Forexample, representative coupling agents can include organic compoundssuch as thioesters, carbodiimides, succinimide esters, diisocyanates,glutaraldehyde, diazobenzenes and hexamethylene diamines. This listingis not intended to be exhaustive of the various classes of couplingagents known in the art but, rather, is exemplary of the more commoncoupling agents. (See Killen and Lindstrom, Jour. Immun. 133:1335-2549(1984); Jansen et al., Immunological Reviews 62:185-216 (1982), andVitetta et al., Science 238:1098 (1987).

In some embodiments, in addition to the compositions and methodsprovided herein, the conjugated activatable antibody can also bemodified for site-specific conjugation through modified amino acidsequences inserted or otherwise included in the activatable antibodysequence. These modified amino acid sequences are designed to allow forcontrolled placement and/or dosage of the conjugated agent within aconjugated activatable antibody. For example, the activatable antibodycan be engineered to include cysteine substitutions at positions onlight and heavy chains that provide reactive thiol groups and do notnegatively impact protein folding and assembly, nor alter antigenbinding. In some embodiments, the activatable antibody can be engineeredto include or otherwise introduce one or more non-natural amino acidresidues within the activatable antibody to provide suitable sites forconjugation. In some embodiments, the activatable antibody can beengineered to include or otherwise introduce enzymatically activatablepeptide sequences within the activatable antibody sequence.

Suitable linkers are described in the literature. (See, for example,Ramakrishnan, S. et al., Cancer Res. 44:201-208 (1984) describing use ofMBS (M-maleimidobenzoyl-N-hydroxysuccinimide ester). See also, U.S. Pat.No. 5,030,719, describing use of halogenated acetyl hydrazide derivativecoupled to an antibody by way of an oligopeptide linker. In someembodiments, suitable linkers include: (i) EDC(1-ethyl-3-(3-dimethylamino-propyl) carbodiimide hydrochloride; (ii)SMPT(4-succinimidyloxycarbonyl-alpha-methyl-alpha-(2-pridyl-dithio)-toluene(Pierce Chem. Co., Cat. (21558G); (iii) SPDP (succinimidyl-6[3-(2-pyridyldithio) propionamido]hexanoate (Pierce Chem. Co., Cat#21651G); (iv) Sulfo-LC-SPDP (sulfosuccinimidyl 6[3-(2-pyridyldithio)-propianamide]hexanoate (Pierce Chem. Co. Cat.#2165-G), and (v) sulfo-NHS (N-hydroxysulfo-succinimide: Pierce Chem.Co., Cat. #24510) conjugated to EDC. Additional linkers include, but arenot limited to, SMCC, sulfo-SMCC, SPDB, or sulfo-SPDB.

The linkers described above contain components that have differentattributes, thus leading to conjugates with differing physio-chemicalproperties. For example, sulfo-NHS esters of alkyl carboxylates are morestable than sulfo-NHS esters of aromatic carboxylates. NHS-estercontaining linkers are less soluble than sulfo-NHS esters. Further, thelinker SMPT contains a sterically hindered disulfide bond, and can formconjugates with increased stability. Disulfide linkages, are in general,less stable than other linkages because the disulfide linkage is cleavedin vitro, resulting in less conjugate available. Sulfo-NHS, inparticular, can enhance the stability of carbodimide couplings.Carbodimide couplings (such as EDC) when used in conjunction withsulfo-NHS, forms esters that are more resistant to hydrolysis than thecarbodimide coupling reaction alone.

In some embodiments, the linkers are cleavable. In some embodiments, thelinkers are non-cleavable. In some embodiments, two or more linkers arepresent. The two or more linkers are all the same, i.e., cleavable ornon-cleavable, or the two or more linkers are different, i.e., at leastone cleavable and at least one non-cleavable.

The present disclosure utilizes several methods for attaching agents toABs: (a) attachment to the carbohydrate moieties of the AB, or (b)attachment to sulfhydryl groups of the AB, or (c) attachment to aminogroups of the AB, or (d) attachment to carboxylate groups of the AB.According to the disclosure, ABs may be covalently attached to an agentthrough an intermediate linker having at least two reactive groups, oneto react with AB and one to react with the agent. The linker, which mayinclude any compatible organic compound, can be chosen such that thereaction with AB (or agent) does not adversely affect AB reactivity andselectivity. Furthermore, the attachment of linker to agent might notdestroy the activity of the agent. Suitable linkers for reaction withoxidized antibodies or oxidized antibody fragments include thosecontaining an amine selected from the group consisting of primary amine,secondary amine, hydrazine, hydrazide, hydroxylamine, phenylhydrazine,semicarbazide and thiosemicarbazide groups. Such reactive functionalgroups may exist as part of the structure of the linker, or may beintroduced by suitable chemical modification of linkers not containingsuch groups.

According to the present disclosure, suitable linkers for attachment toreduced ABs include those having certain reactive groups capable ofreaction with a sulfhydryl group of a reduced antibody or fragment. Suchreactive groups include, but are not limited to: reactive haloalkylgroups (including, for example, haloacetyl groups), p-mercuribenzoategroups and groups capable of Michael-type addition reactions (including,for example, maleimides and groups of the type described by Mitra andLawton, 1979, J. Amer. Chem. Soc. 101: 3097-3110).

According to the present disclosure, suitable linkers for attachment toneither oxidized nor reduced Abs include those having certain functionalgroups capable of reaction with the primary amino groups present inunmodified lysine residues in the Ab. Such reactive groups include, butare not limited to, NHS carboxylic or carbonic esters, sulfo-NHScarboxylic or carbonic esters, 4-nitrophenyl carboxylic or carbonicesters, pentafluorophenyl carboxylic or carbonic esters, acylimidazoles, isocyanates, and isothiocyanates.

According to the present disclosure, suitable linkers for attachment toneither oxidized nor reduced Abs include those having certain functionalgroups capable of reaction with the carboxylic acid groups present inaspartate or glutamate residues in the Ab, which have been activatedwith suitable reagents. Suitable activating reagents include EDC, withor without added NHS or sulfo-NHS, and other dehydrating agents utilizedfor carboxamide formation. In these instances, the functional groupspresent in the suitable linkers would include primary and secondaryamines, hydrazines, hydroxylamines, and hydrazides.

The agent may be attached to the linker before or after the linker isattached to the AB. In certain applications it may be desirable to firstproduce an AB-linker intermediate in which the linker is free of anassociated agent. Depending upon the particular application, a specificagent may then be covalently attached to the linker. In someembodiments, the AB is first attached to the MM, CM and associatedlinkers and then attached to the linker for conjugation purposes.

Branched Linkers:

In specific embodiments, branched linkers that have multiple sites forattachment of agents are utilized. For multiple site linkers, a singlecovalent attachment to an AB would result in an AB-linker intermediatecapable of binding an agent at a number of sites. The sites may bealdehyde or sulfhydryl groups or any chemical site to which agents canbe attached.

In some embodiments, higher specific activity (or higher ratio of agentsto AB) can be achieved by attachment of a single site linker at aplurality of sites on the AB. This plurality of sites may be introducedinto the AB by either of two methods. First, one may generate multiplealdehyde groups and/or sulfhydryl groups in the same AB. Second, one mayattach to an aldehyde or sulfhydryl of the AB a “branched linker” havingmultiple functional sites for subsequent attachment to linkers. Thefunctional sites of the branched linker or multiple site linker may bealdehyde or sulfhydryl groups, or may be any chemical site to whichlinkers may be attached. Still higher specific activities may beobtained by combining these two approaches, that is, attaching multiplesite linkers at several sites on the AB.

Cleavable Linkers:

Peptide linkers that are susceptible to cleavage by enzymes of thecomplement system, such as but not limited to u-plasminogen activator,tissue plasminogen activator, trypsin, plasmin, or another enzyme havingproteolytic activity may be used in one embodiment of the presentdisclosure. According to one method of the present disclosure, an agentis attached via a linker susceptible to cleavage by complement. Theantibody is selected from a class that can activate complement. Theantibody-agent conjugate, thus, activates the complement cascade andreleases the agent at the target site. According to another method ofthe present disclosure, an agent is attached via a linker susceptible tocleavage by enzymes having a proteolytic activity such as au-plasminogen activator, a tissue plasminogen activator, plasmin, ortrypsin. These cleavable linkers are useful in conjugated activatableantibodies that include an extracellular toxin, e.g., by way ofnon-limiting example, any of the extracellular toxins shown in Table 11.

Non-limiting examples of cleavable linker sequences are provided inTable 13.

TABLE 13 Exemplary Linker Sequences for ConjugationTypes of Cleavable Sequences Amino Acid SequencePlasmin cleavable sequences Pro-urokinase PRFKIIGG (SEQ ID NO: 396)PRFRIIGG (SEQ ID NO: 397) TGFβ SSRHRRALD (SEQ ID NO: 398) PlasminogenRKSSIIIRMRDVVL (SEQ ID NO: 399) StaphylokinaseSSSFDKGKYKKGDDA (SEQ ID NO: 400) SSSFDKGKYKRGDDA (SEQ ID NO: 401)Factor Xa cleavable sequences IEGR (SEQ ID NO: 402)IDGR (SEQ ID NO: 403) GGSIDGR (SEQ ID NO: 404) MMP cleavable sequencesGelatinase A PLGLWA (SEQ ID NO: 405) Collagenase cleavable sequencesCalf skin collagen (α1(I) chain) GPQGIAGQ (SEQ ID NO: 406)Calf skin collagen (α2(I) chain) GPQGLLGA (SEQ ID NO: 407)Bovine cartilage collagen (α1(II) chain) GIAGQ (SEQ ID NO: 408)Human liver collagen (α1(III) chain) GPLGIAGI (SEQ ID NO: 409) Human α₂MGPEGLRVG (SEQ ID NO: 410) Human PZP YGAGLGVV (SEQ ID NO: 411)AGLGVVER (SEQ ID NO: 412) AGLGISST (SEQ ID NO: 413) Rat α₁MEPQALAMS (SEQ ID NO: 414) QALAMSAI (SEQ ID NO: 415) Rat α₂MAAYHLVSQ (SEQ ID NO: 416) MDAFLESS (SEQ ID NO: 417) Rat α₁I₃(2J)ESLPVVAV (SEQ ID NO: 418) Rat α₁I₃(2J) SAPAVESE (SEQ ID NO: 419)Human fibroblast collagenase DVAQFVLT (SEQ ID NO: 420)(autolytic cleavages) VAQFVLTE (SEQ ID NO: 421)AQFVLTEG (SEQ ID NO: 422) PVQPIGPQ (SEQ ID NO: 423)

In addition, agents may be attached via disulfide bonds (for example,the disulfide bonds on a cysteine molecule) to the AB. Since many tumorsnaturally release high levels of glutathione (a reducing agent) this canreduce the disulfide bonds with subsequent release of the agent at thesite of delivery. In some embodiments, the reducing agent that wouldmodify a CM would also modify the linker of the conjugated activatableantibody.

Spacers and Cleavable Elements:

In some embodiments, it may be necessary to construct the linker in sucha way as to optimize the spacing between the agent and the AB of theactivatable antibody. This may be accomplished by use of a linker of thegeneral structure:

W—(CH₂)n-Q

whereinW is either —NH—CH₂— or —CH₂—;Q is an amino acid, peptide; andn is an integer from 0 to 20.

In some embodiments, the linker may comprise a spacer element and acleavable element. The spacer element serves to position the cleavableelement away from the core of the AB such that the cleavable element ismore accessible to the enzyme responsible for cleavage. Certain of thebranched linkers described above may serve as spacer elements.

Throughout this discussion, it should be understood that the attachmentof linker to agent (or of spacer element to cleavable element, orcleavable element to agent) need not be particular mode of attachment orreaction. Any reaction providing a product of suitable stability andbiological compatibility is acceptable.

Serum Complement and Selection of Linkers:

According to one method of the present disclosure, when release of anagent is desired, an AB that is an antibody of a class that can activatecomplement is used. The resulting conjugate retains both the ability tobind antigen and activate the complement cascade. Thus, according tothis embodiment of the present disclosure, an agent is joined to one endof the cleavable linker or cleavable element and the other end of thelinker group is attached to a specific site on the AB. For example, ifthe agent has an hydroxy group or an amino group, it may be attached tothe carboxy terminus of a peptide, amino acid or other suitably chosenlinker via an ester or amide bond, respectively. For example, suchagents may be attached to the linker peptide via a carbodimide reaction.If the agent contains functional groups that would interfere withattachment to the linker, these interfering functional groups can beblocked before attachment and deblocked once the product conjugate orintermediate is made. The opposite or amino terminus of the linker isthen used either directly or after further modification for binding toan AB that is capable of activating complement.

Linkers (or spacer elements of linkers) may be of any desired length,one end of which can be covalently attached to specific sites on the ABof the activatable antibody. The other end of the linker or spacerelement may be attached to an amino acid or peptide linker.

Thus when these conjugates bind to antigen in the presence of complementthe amide or ester bond that attaches the agent to the linker will becleaved, resulting in release of the agent in its active form. Theseconjugates, when administered to a subject, will accomplish delivery andrelease of the agent at the target site, and are particularly effectivefor the in vivo delivery of pharmaceutical agents, antibiotics,antimetabolites, antiproliferative agents and the like as presented inbut not limited to those in Table 11.

Linkers for Release without Complement Activation:

In yet another application of targeted delivery, release of the agentwithout complement activation is desired since activation of thecomplement cascade will ultimately lyse the target cell. Hence, thisapproach is useful when delivery and release of the agent should beaccomplished without killing the target cell. Such is the goal whendelivery of cell mediators such as hormones, enzymes, corticosteroids,neurotransmitters, genes or enzymes to target cells is desired. Theseconjugates may be prepared by attaching the agent to an AB that is notcapable of activating complement via a linker that is mildly susceptibleto cleavage by serum proteases. When this conjugate is administered toan individual, antigen-antibody complexes will form quickly whereascleavage of the agent will occur slowly, thus resulting in release ofthe compound at the target site.

Biochemical Cross Linkers:

In some embodiments, the activatable antibody may be conjugated to oneor more therapeutic agents using certain biochemical cross-linkers.Cross-linking reagents form molecular bridges that tie togetherfunctional groups of two different molecules. To link two differentproteins in a step-wise manner, hetero-bifunctional cross-linkers can beused that eliminate unwanted homopolymer formation.

Peptidyl linkers cleavable by lysosomal proteases are also useful, forexample, Val-Cit, Val-Ala or other dipeptides. In addition, acid-labilelinkers cleavable in the low-pH environment of the lysosome may be used,for example: bis-sialyl ether. Other suitable linkers includecathepsin-labile substrates, particularly those that show optimalfunction at an acidic pH.

Exemplary hetero-bifunctional cross-linkers are referenced in Table 14.

TABLE 14 Exemplary Hetero-Bifunctional Cross Linkers HETERO-BIFUNCTIONALCROSS-LINKERS Spacer Arm Length after Reactive Advantages andcross-linking Linker Toward Applications (Angstroms) SMPT Primary aminesGreater stability 11.2 Å Sulfhydryls SPDP Primary amines Thiolation  6.8Å Sulfhydryls Cleavable cross- linking LC-SPDP Primary amines Extendedspacer arm 15.6 Å Sulfhydryls Sulfo-LC- Primary amines Extender spacerarm 15.6 Å SPDP Sulfhydryls Water-soluble SMCC Primary amines Stablemaleimide 11.6 Å reactive group Sulfhydryls Enzyme-antibody conjugationHapten-carrier protein conjugation Sulfo-SMCC Primary amines Stablemaleimide 11.6 Å reactive group Sulfhydryls Water-solubleEnzyme-antibody conjugation MBS Primary amines Enzyme-antibody  9.9 Åconjugation Sulfhydryls Hapten-carrier protein conjugation Sulfo-MBSPrimary amines Water-soluble  9.9 Å Sulfhydryls SIAB Primary aminesEnzyme-antibody 10.6 Å conjugation Sulfhydryls Sulfo-SIAB Primary aminesWater-soluble 10.6 Å Sulfhydryls SMPB Primary amines Extended spacer arm14.5 Å Sulfhydryls Enzyme-antibody conjugation Sulfo-SMPB Primary aminesExtended spacer arm 14.5 Å Sulfhydryls Water-soluble EDE/Sulfo- Primaryamines Hapten-Carrier 0 NHS conjugation Carboxyl groups ABHCarbohydrates Reacts with sugar 11.9 Å groups Nonselective

Non-Cleavable Linkers or Direct Attachment:

In some embodiments of the disclosure, the conjugate may be designed sothat the agent is delivered to the target but not released. This may beaccomplished by attaching an agent to an AB either directly or via anon-cleavable linker.

These non-cleavable linkers may include amino acids, peptides, D-aminoacids or other organic compounds that may be modified to includefunctional groups that can subsequently be utilized in attachment to ABsby the methods described herein. A-general formula for such an organiclinker could be

W—(CH₂)n-Q

whereinW is either —NH—CH₂— or —CH₂—;Q is an amino acid, peptide; andn is an integer from 0 to 20.

Non-Cleavable Conjugates:

In some embodiments, a compound may be attached to ABs that do notactivate complement. When using ABs that are incapable of complementactivation, this attachment may be accomplished using linkers that aresusceptible to cleavage by activated complement or using linkers thatare not susceptible to cleavage by activated complement.

The antibodies disclosed herein can also be formulated asimmunoliposomes. Liposomes containing the antibody are prepared bymethods known in the art, such as described in Epstein et al., Proc.Natl. Acad. Sci. USA, 82: 3688 (1985); Hwang et al., Proc. Natl Acad.Sci. USA, 77: 4030 (1980); and U.S. Pat. Nos. 4,485,045 and 4,544,545.Liposomes with enhanced circulation time are disclosed in U.S. Pat. No.5,013,556.

Particularly useful liposomes can be generated by the reverse-phaseevaporation method with a lipid composition comprisingphosphatidylcholine, cholesterol, and PEG-derivatizedphosphatidylethanolamine (PEG-PE). Liposomes are extruded throughfilters of defined pore size to yield liposomes with the desireddiameter. Fab′ fragments of the antibody of the present disclosure canbe conjugated to the liposomes as described in Martin et al., J. Biol.Chem., 257: 286-288 (1982) via a disulfide-interchange reaction.

DEFINITIONS

Unless otherwise defined, scientific and technical terms used inconnection with the present disclosure shall have the meanings that arecommonly understood by those of ordinary skill in the art. The term “a”entity or “an” entity refers to one or more of that entity. For example,a compound refers to one or more compounds. As such, the terms “a”,“an”, “one or more” and “at least one” can be used interchangeably.Further, unless otherwise required by context, singular terms shallinclude pluralities and plural terms shall include the singular.Generally, nomenclatures utilized in connection with, and techniques of,cell and tissue culture, molecular biology, and protein and oligo- orpolynucleotide chemistry and hybridization described herein are thosewell-known and commonly used in the art. Standard techniques are usedfor recombinant DNA, oligonucleotide synthesis, and tissue culture andtransformation (e.g., electroporation, lipofection). Enzymatic reactionsand purification techniques are performed according to manufacturer'sspecifications or as commonly accomplished in the art or as describedherein. The foregoing techniques and procedures are generally performedaccording to conventional methods well known in the art and as describedin various general and more specific references that are cited anddiscussed throughout the present specification. See e.g., Sambrook etal. Molecular Cloning: A Laboratory Manual (2d ed., Cold Spring HarborLaboratory Press, Cold Spring Harbor, N.Y. (1989)). The nomenclaturesutilized in connection with, and the laboratory procedures andtechniques of, analytical chemistry, synthetic organic chemistry, andmedicinal and pharmaceutical chemistry described herein are thosewell-known and commonly used in the art. Standard techniques are usedfor chemical syntheses, chemical analyses, pharmaceutical preparation,formulation, and delivery, and treatment of patients.

As utilized in accordance with the present disclosure, the followingterms, unless otherwise indicated, shall be understood to have thefollowing meanings:

As used herein, the term “antibody” refers to immunoglobulin moleculesand immunologically active portions of immunoglobulin (Ig) molecules,i.e., molecules that contain an antigen binding site that specificallybinds (immunoreacts with) an antigen. By “specifically bind” or“immunoreacts with” or “immunospecifically bind” is meant that theantibody reacts with one or more antigenic determinants of the desiredantigen and does not react with other polypeptides or binds at muchlower affinity (K_(d)>10⁻⁶). Antibodies include, but are not limited to,polyclonal, monoclonal, chimeric, domain antibody, single chain, Fab,and F(ab′)₂ fragments, scFvs, and an Fab expression library.

The basic antibody structural unit is known to comprise a tetramer. Eachtetramer is composed of two identical pairs of polypeptide chains, eachpair having one “light” (about 25 kDa) and one “heavy” chain (about50-70 kDa). The amino-terminal portion of each chain includes a variableregion of about 100 to 110 or more amino acids primarily responsible forantigen recognition. The carboxy-terminal portion of each chain definesa constant region primarily responsible for effector function. Ingeneral, antibody molecules obtained from humans relate to any of theclasses IgG, IgM, IgA, IgE and IgD, which differ from one another by thenature of the heavy chain present in the molecule. Certain classes havesubclasses as well, such as IgG₁, IgG₂, and others. Furthermore, inhumans, the light chain may be a kappa chain or a lambda chain.

The term “monoclonal antibody” (mAb) or “monoclonal antibodycomposition”, as used herein, refers to a population of antibodymolecules that contain only one molecular species of antibody moleculeconsisting of a unique light chain gene product and a unique heavy chaingene product. In particular, the complementarity determining regions(CDRs) of the monoclonal antibody are identical in all the molecules ofthe population. MAbs contain an antigen binding site capable ofimmunoreacting with a particular epitope of the antigen characterized bya unique binding affinity for it.

The term “antigen-binding site” or “binding portion” refers to the partof the immunoglobulin molecule that participates in antigen binding. Theantigen binding site is formed by amino acid residues of the N-terminalvariable (“V”) regions of the heavy (“H”) and light (“L”) chains. Threehighly divergent stretches within the V regions of the heavy and lightchains, referred to as “hypervariable regions,” are interposed betweenmore conserved flanking stretches known as “framework regions,” or“FRs”. Thus, the term “FR” refers to amino acid sequences that arenaturally found between, and adjacent to, hypervariable regions inimmunoglobulins. In an antibody molecule, the three hypervariableregions of a light chain and the three hypervariable regions of a heavychain are disposed relative to each other in three dimensional space toform an antigen-binding surface. The antigen-binding surface iscomplementary to the three-dimensional surface of a bound antigen, andthe three hypervariable regions of each of the heavy and light chainsare referred to as “complementarity-determining regions,” or “CDRs.” Theassignment of amino acids to each domain is in accordance with thedefinitions of Kabat Sequences of Proteins of Immunological Interest(National Institutes of Health, Bethesda, Md. (1987 and 1991)), orChothia & Lesk J. Mol. Biol. 196:901-917 (1987), Chothia et al. Nature342:878-883 (1989).

As used herein, the term “epitope” includes any protein determinantcapable of specific binding to an immunoglobulin, an scFv, or a T-cellreceptor. The term “epitope” includes any protein determinant capable ofspecific binding to an immunoglobulin or T-cell receptor. Epitopicdeterminants usually consist of chemically active surface groupings ofmolecules such as amino acids or sugar side chains and usually havespecific three dimensional structural characteristics, as well asspecific charge characteristics. For example, antibodies may be raisedagainst N-terminal or C-terminal peptides of a polypeptide. An antibodyis said to specifically bind an antigen when the dissociation constantis ≦1 μM; in some embodiments, ≦100 nM and in some embodiments, ≦10 nM.

As used herein, the terms “specific binding,” “immunological binding,”and “immunological binding properties” refer to the non-covalentinteractions of the type which occur between an immunoglobulin moleculeand an antigen for which the immunoglobulin is specific. The strength,or affinity of immunological binding interactions can be expressed interms of the dissociation constant (K_(d)) of the interaction, wherein asmaller K_(d) represents a greater affinity. Immunological bindingproperties of selected polypeptides can be quantified using methods wellknown in the art. One such method entails measuring the rates ofantigen-binding site/antigen complex formation and dissociation, whereinthose rates depend on the concentrations of the complex partners, theaffinity of the interaction, and geometric parameters that equallyinfluence the rate in both directions. Thus, both the “on rate constant”(K_(on)) and the “off rate constant” (K_(off)) can be determined bycalculation of the concentrations and the actual rates of associationand dissociation. (See Nature 361:186-87 (1993)). The ratio ofK_(off)/K_(on) enables the cancellation of all parameters not related toaffinity, and is equal to the dissociation constant K_(d). (See,generally, Davies et al. (1990) Annual Rev Biochem 59:439-473). Anantibody of the present disclosure is said to specifically bind to thetarget, when the binding constant (K_(d)) is ≦1 μM, in someembodiments≦100 nM, in some embodiments≦10 nM, and in someembodiments≦100 pM to about 1 pM, as measured by assays such asradioligand binding assays or similar assays known to those skilled inthe art.

The term “isolated polynucleotide” as used herein shall mean apolynucleotide of genomic, cDNA, or synthetic origin or some combinationthereof, which by virtue of its origin the “isolated polynucleotide” (1)is not associated with all or a portion of a polynucleotide in which the“isolated polynucleotide” is found in nature, (2) is operably linked toa polynucleotide which it is not linked to in nature, or (3) does notoccur in nature as part of a larger sequence. Polynucleotides inaccordance with the disclosure include the nucleic acid moleculesencoding the heavy chain immunoglobulin molecules shown herein, andnucleic acid molecules encoding the light chain immunoglobulin moleculesshown herein.

The term “isolated protein” referred to herein means a protein of cDNA,recombinant RNA, or synthetic origin or some combination thereof, whichby virtue of its origin, or source of derivation, the “isolated protein”(1) is not associated with proteins found in nature, (2) is free ofother proteins from the same source, e.g., free of murine proteins, (3)is expressed by a cell from a different species, or (4) does not occurin nature.

The term “polypeptide” is used herein as a generic term to refer tonative protein, fragments, or analogs of a polypeptide sequence. Hence,native protein fragments, and analogs are species of the polypeptidegenus. Polypeptides in accordance with the disclosure comprise the heavychain immunoglobulin molecules shown herein, and the light chainimmunoglobulin molecules shown herein, as well as antibody moleculesformed by combinations comprising the heavy chain immunoglobulinmolecules with light chain immunoglobulin molecules, such as kappa lightchain immunoglobulin molecules, and vice versa, as well as fragments andanalogs thereof.

The term “naturally-occurring” as used herein as applied to an objectrefers to the fact that an object can be found in nature. For example, apolypeptide or polynucleotide sequence that is present in an organism(including viruses) that can be isolated from a source in nature andthat has not been intentionally modified by man in the laboratory orotherwise is naturally-occurring.

The term “operably linked” as used herein refers to positions ofcomponents so described are in a relationship permitting them tofunction in their intended manner. A control sequence “operably linked”to a coding sequence is ligated in such a way that expression of thecoding sequence is achieved under conditions compatible with the controlsequences.

The term “control sequence” as used herein refers to polynucleotidesequences that are necessary to effect the expression and processing ofcoding sequences to which they are ligated. The nature of such controlsequences differs depending upon the host organism in prokaryotes, suchcontrol sequences generally include promoter, ribosomal binding site,and transcription termination sequence in eukaryotes, generally, suchcontrol sequences include promoters and transcription terminationsequence. The term “control sequences” is intended to include, at aminimum, all components whose presence is essential for expression andprocessing, and can also include additional components whose presence isadvantageous, for example, leader sequences and fusion partnersequences. The term “polynucleotide” as referred to herein meansnucleotides of at least 10 bases in length, either ribonucleotides ordeoxynucleotides or a modified form of either type of nucleotide. Theterm includes single and double stranded forms of DNA.

The term oligonucleotide referred to herein includes naturallyoccurring, and modified nucleotides linked together by naturallyoccurring, and non-naturally occurring oligonucleotide linkages.Oligonucleotides are a polynucleotide subset generally comprising alength of 200 bases or fewer. In some embodiments, oligonucleotides are10 to 60 bases in length and in some embodiments, 12, 13, 14, 15, 16,17, 18, 19, or 20 to 40 bases in length. Oligonucleotides are usuallysingle stranded, e.g., for probes, although oligonucleotides may bedouble stranded, e.g., for use in the construction of a gene mutant.Oligonucleotides of the disclosure are either sense or antisenseoligonucleotides.

The term “naturally occurring nucleotides” referred to herein includesdeoxyribonucleotides and ribonucleotides. The term “modifiednucleotides” referred to herein includes nucleotides with modified orsubstituted sugar groups and the like. The term “oligonucleotidelinkages” referred to herein includes oligonucleotide linkages such asphosphorothioate, phosphorodithioate, phosphoroselerloate,phosphorodiselenoate, phosphoroanilothioate, phoshoraniladate,phosphoronmidate, and the like. See e.g., LaPlanche et al. Nucl. AcidsRes. 14:9081 (1986); Stec et al. J. Am. Chem. Soc. 106:6077 (1984),Stein et al. Nucl. Acids Res. 16:3209 (1988), Zon et al. Anti CancerDrug Design 6:539 (1991); Zon et al. Oligonucleotides and Analogues: APractical Approach, pp. 87-108 (F. Eckstein, Ed., Oxford UniversityPress, Oxford England (1991)); Stec et al. U.S. Pat. No. 5,151,510,Uhlmann and Peyman Chemical Reviews 90:543 (1990). An oligonucleotidecan include a label for detection, if desired.

As used herein, the twenty conventional amino acids and theirabbreviations follow conventional usage. See Immunology—A Synthesis (2ndEdition, E. S. Golub and D. R. Green, Eds., Sinauer Associates,Sunderland, Mass. (1991)). Stereoisomers (e.g., D-amino acids) of thetwenty conventional amino acids, unnatural amino acids such as α-,α-disubstituted amino acids, N-alkyl amino acids, lactic acid, and otherunconventional amino acids may also be suitable components forpolypeptides of the present disclosure. Examples of unconventional aminoacids include: 4 hydroxyproline, γ-carboxyglutamate,ε-N,N,N-trimethyllysine, ε-N-acetyllysine, O-phosphoserine,N-acetylserine, N-formylmethionine, 3-methylhistidine, 5-hydroxylysine,σ-N-methylarginine, and other similar amino acids and imino acids (e.g.,4-hydroxyproline). In the polypeptide notation used herein, theleft-hand direction is the amino terminal direction and the right-handdirection is the carboxy-terminal direction, in accordance with standardusage and convention.

Similarly, unless specified otherwise, the left-hand end ofsingle-stranded polynucleotide sequences is the 5′ end the left-handdirection of double-stranded polynucleotide sequences is referred to asthe 5′ direction. The direction of 5′ to 3′ addition of nascent RNAtranscripts is referred to as the transcription direction sequenceregions on the DNA strand having the same sequence as the RNA and thatare 5′ to the 5′ end of the RNA transcript are referred to as “upstreamsequences”, sequence regions on the DNA strand having the same sequenceas the RNA and that are 3′ to the 3′ end of the RNA transcript arereferred to as “downstream sequences”.

As applied to polypeptides, the term “substantial identity” means thattwo peptide sequences, when optimally aligned, such as by the programsGAP or BESTFIT using default gap weights, share at least 80 percentsequence identity, in some embodiments, at least 90 percent sequenceidentity, in some embodiments, at least 95 percent sequence identity,and in some embodiments, at least 99 percent sequence identity.

In some embodiments, residue positions that are not identical differ byconservative amino acid substitutions.

As discussed herein, minor variations in the amino acid sequences ofantibodies or immunoglobulin molecules are contemplated as beingencompassed by the present disclosure, providing that the variations inthe amino acid sequence maintain at least 75%, in some embodiments, atleast 80%, 90%, 95%, and in some embodiments, 99%. In particular,conservative amino acid replacements are contemplated. Conservativereplacements are those that take place within a family of amino acidsthat are related in their side chains. Genetically encoded amino acidsare generally divided into families: (1) acidic amino acids areaspartate, glutamate; (2) basic amino acids are lysine, arginine,histidine; (3) non-polar amino acids are alanine, valine, leucine,isoleucine, proline, phenylalanine, methionine, tryptophan, and (4)uncharged polar amino acids are glycine, asparagine, glutamine,cysteine, serine, threonine, tyrosine. The hydrophilic amino acidsinclude arginine, asparagine, aspartate, glutamine, glutamate,histidine, lysine, serine, and threonine. The hydrophobic amino acidsinclude alanine, cysteine, isoleucine, leucine, methionine,phenylalanine, proline, tryptophan, tyrosine and valine. Other familiesof amino acids include (i) serine and threonine, which are thealiphatic-hydroxy family; (ii) asparagine and glutamine, which are theamide containing family; (iii) alanine, valine, leucine and isoleucine,which are the aliphatic family; and (iv) phenylalanine, tryptophan, andtyrosine, which are the aromatic family. For example, it is reasonableto expect that an isolated replacement of a leucine with an isoleucineor valine, an aspartate with a glutamate, a threonine with a serine, ora similar replacement of an amino acid with a structurally related aminoacid will not have a major effect on the binding or properties of theresulting molecule, especially if the replacement does not involve anamino acid within a framework site. Whether an amino acid change resultsin a functional peptide can readily be determined by assaying thespecific activity of the polypeptide derivative. Assays are described indetail herein. Fragments or analogs of antibodies or immunoglobulinmolecules can be readily prepared by those of ordinary skill in the art.Suitable amino- and carboxy-termini of fragments or analogs occur nearboundaries of functional domains. Structural and functional domains canbe identified by comparison of the nucleotide and/or amino acid sequencedata to public or proprietary sequence databases. In some embodiments,computerized comparison methods are used to identify sequence motifs orpredicted protein conformation domains that occur in other proteins ofknown structure and/or function. Methods to identify protein sequencesthat fold into a known three-dimensional structure are known. Bowie etal. Science 253:164 (1991). Thus, the foregoing examples demonstratethat those of skill in the art can recognize sequence motifs andstructural conformations that may be used to define structural andfunctional domains in accordance with the disclosure.

Suitable amino acid substitutions are those that: (1) reducesusceptibility to proteolysis, (2) reduce susceptibility to oxidation,(3) alter binding affinity for forming protein complexes, (4) alterbinding affinities, and (5) confer or modify other physicochemical orfunctional properties of such analogs. Analogs can include variousmuteins of a sequence other than the naturally-occurring peptidesequence. For example, single or multiple amino acid substitutions (forexample, conservative amino acid substitutions) may be made in thenaturally-occurring sequence (for example, in the portion of thepolypeptide outside the domain(s) forming intermolecular contacts. Aconservative amino acid substitution should not substantially change thestructural characteristics of the parent sequence (e.g., a replacementamino acid should not tend to break a helix that occurs in the parentsequence, or disrupt other types of secondary structure thatcharacterizes the parent sequence). Examples of art-recognizedpolypeptide secondary and tertiary structures are described in Proteins,Structures and Molecular Principles (Creighton, Ed., W. H. Freeman andCompany, New York (1984)); Introduction to Protein Structure (C. Brandenand J. Tooze, eds., Garland Publishing, New York, N.Y. (1991)); andThornton et at. Nature 354:105 (1991).

The term “polypeptide fragment” as used herein refers to a polypeptidethat has an amino terminal and/or carboxy-terminal deletion and/or oneor more internal deletion(s), but where the remaining amino acidsequence is identical to the corresponding positions in thenaturally-occurring sequence deduced, for example, from a full lengthcDNA sequence. Fragments typically are at least 5, 6, 8 or 10 aminoacids long, in some embodiments, at least 14 amino acids long, in someembodiments, at least 20 amino acids long, usually at least 50 aminoacids long, and in some embodiments, at least 70 amino acids long. Theterm “analog” as used herein refers to polypeptides that are comprisedof a segment of at least 25 amino acids that has substantial identity toa portion of a deduced amino acid sequence and that has specific bindingto the target, under suitable binding conditions. Typically, polypeptideanalogs comprise a conservative amino acid substitution (or addition ordeletion) with respect to the naturally-occurring sequence. Analogstypically are at least 20 amino acids long, in some embodiments, atleast 50 amino acids long or longer, and can often be as long as afull-length naturally-occurring polypeptide.

The term “agent” is used herein to denote a chemical compound, a mixtureof chemical compounds, a biological macromolecule, or an extract madefrom biological materials.

As used herein, the terms “label” or “labeled” refers to incorporationof a detectable marker, e.g., by incorporation of a radiolabeled aminoacid or attachment to a polypeptide of biotinyl moieties that can bedetected by marked avidin (e.g., streptavidin containing a fluorescentmarker or enzymatic activity that can be detected by optical orcalorimetric methods). In certain situations, the label or marker canalso be therapeutic. Various methods of labeling polypeptides andglycoproteins are known in the art and may be used. Examples of labelsfor polypeptides include, but are not limited to, the following:radioisotopes or radionuclides (e.g., ³H, ¹⁴C, ¹⁵N, ³⁵S, ⁹⁰Y, ⁹⁹Tc,¹¹¹In, ¹²⁵I, ¹³¹I), fluorescent labels (e.g., FITC, rhodamine,lanthanide phosphors), enzymatic labels (e.g., horseradish peroxidase,p-galactosidase, luciferase, alkaline phosphatase), chemiluminescent,biotinyl groups, predetermined polypeptide epitopes recognized by asecondary reporter (e.g., leucine zipper pair sequences, binding sitesfor secondary antibodies, metal binding domains, epitope tags). In someembodiments, labels are attached by spacer arms of various lengths toreduce potential steric hindrance. The term “pharmaceutical agent ordrug” as used herein refers to a chemical compound or compositioncapable of inducing a desired therapeutic effect when properlyadministered to a patient.

Other chemistry terms herein are used according to conventional usage inthe art, as exemplified by The McGraw-Hill Dictionary of Chemical Terms(Parker, S., Ed., McGraw-Hill, San Francisco (1985)).

As used herein, “substantially pure” means an object species is thepredominant species present (i.e., on a molar basis it is more abundantthan any other individual species in the composition), and in someembodiments, a substantially purified fraction is a composition whereinthe object species comprises at least about 50 percent (on a molarbasis) of all macromolecular species present.

Generally, a substantially pure composition will comprise more thanabout 80 percent of all macromolecular species present in thecomposition, in some embodiments, more than about 85%, 90%, 95%, and99%. In some embodiments, the object species is purified to essentialhomogeneity (contaminant species cannot be detected in the compositionby conventional detection methods) wherein the composition consistsessentially of a single macromolecular species.

The term patient includes human and veterinary subjects.

Antibodies and/or activatable antibodies of the disclosure specificallybind a given target, e.g., a human target protein such as human PDL1.Also included in the disclosure are antibodies and/or activatableantibodies that bind to the same epitope as the antibodies and/oractivatable antibodies described herein. Also included in the disclosureare antibodies and/or antibodies activatable antibodies that competewith an anti-PDL1 antibody and/or an anti-PDL activatable antibodydescribed herein for binding to PDL1, e.g., human PDL1. Also included inthe disclosure are antibodies and/or antibodies activatable antibodiesthat cross-compete with an anti-PDL1 antibody and/or an anti-PDL1activatable antibody described herein for binding to PDL1, e.g., humanPDL1.

Those skilled in the art will recognize that it is possible todetermine, without undue experimentation, if a monoclonal antibody(e.g., a murine monoclonal or humanized antibody) has the samespecificity as a monoclonal antibody used in the methods describedherein by ascertaining whether the former prevents the latter frombinding to the target. If the monoclonal antibody being tested competeswith the monoclonal antibody of the disclosure, as shown by a decreasein binding by the monoclonal antibody of the disclosure, then the twomonoclonal antibodies bind to the same, or a closely related, epitope.An alternative method for determining whether a monoclonal antibody hasthe specificity of a monoclonal antibody of the disclosure is topre-incubate the monoclonal antibody of the disclosure with the targetand then add the monoclonal antibody being tested to determine if themonoclonal antibody being tested is inhibited in its ability to bind thetarget. If the monoclonal antibody being tested is inhibited then, inall likelihood, it has the same, or functionally equivalent, epitopicspecificity as the monoclonal antibody of the disclosure.

Multispecific Activatable Antibodies

The disclosure also provides multispecific anti-PDL1 activatableantibodies. The multispecific activatable antibodies provided herein aremultispecific antibodies that recognize PDL1 and at least one or moredifferent antigens or epitopes and that include at least one maskingmoiety (MM) linked to at least one antigen- or epitope-binding domain ofthe multispecific antibody such that coupling of the MM reduces theability of the antigen- or epitope-binding domain to bind its target. Insome embodiments, the MM is coupled to the antigen- or epitope-bindingdomain of the multispecific antibody via a cleavable moiety (CM) thatfunctions as a substrate for at least one protease. The activatablemultispecific antibodies provided herein are stable in circulation,activated at intended sites of therapy and/or diagnosis but not innormal, i.e., healthy tissue, and, when activated, exhibit binding to atarget that is at least comparable to the corresponding, unmodifiedmultispecific antibody.

In some embodiments, the multispecific activatable antibodies aredesigned to engage immune effector cells, also referred to herein asimmune-effector cell engaging multispecific activatable antibodies. Insome embodiments, the multispecific activatable antibodies are designedto engage leukocytes, also referred to herein as leukocyte engagingmultispecific activatable antibodies. In some embodiments, themultispecific activatable antibodies are designed to engage T cells,also referred to herein as T-cell engaging multispecific activatableantibodies. In some embodiments, the multispecific activatableantibodies engage a surface antigen on a leukocyte, such as on a T cell,on a natural killer (NK) cell, on a myeloid mononuclear cell, on amacrophage, and/or on another immune effector cell. In some embodiments,the immune effector cell is a leukocyte. In some embodiments, the immuneeffector cell is a T cell. In some embodiments, the immune effector cellis a NK cell. In some embodiments, the immune effector cell is amononuclear cell, such as a myeloid mononuclear cell. In someembodiments, the multispecific activatable antibodies are designed tobind or otherwise interact with more than one target and/or more thanone epitope, also referred to herein as multi-antigen targetingactivatable antibodies. As used herein, the terms “target” and “antigen”are used interchangeably.

In some embodiments, immune effector cell engaging multispecificactivatable antibodies of the disclosure include a targeting antibody orantigen-binding fragment thereof that binds PDL1 and an immune effectorcell engaging antibody or antigen-binding portion thereof, where atleast one of the targeting antibody or antigen-binding fragment thereofand/or the immune effector cell engaging antibody or antigen-bindingportion thereof is masked. In some embodiments, the immune effector cellengaging antibody or antigen binding fragment thereof includes a firstantibody or antigen-binding fragment thereof (AB1) that binds a first,immune effector cell engaging target, where the AB1 is attached to amasking moiety (MM1) such that coupling of the MM1 reduces the abilityof the AB1 to bind the first target. In some embodiments, the targetingantibody or antigen-binding fragment thereof includes a second antibodyor fragment thereof that includes a second antibody or antigen-bindingfragment thereof (AB2) that binds PDL1, where the AB2 is attached to amasking moiety (MM2) such that coupling of the MM2 reduces the abilityof the AB2 to bind PDL1. In some embodiments, the immune effector cellengaging antibody or antigen binding fragment thereof includes a firstantibody or antigen-binding fragment thereof (AB1) that binds a first,immune effector cell engaging target, where the AB1 is attached to amasking moiety (MM1) such that coupling of the MM1 reduces the abilityof the AB1 to bind the first target, and the targeting antibody orantigen-binding fragment thereof includes a second antibody or fragmentthereof that includes a second antibody or antigen-binding fragmentthereof (AB2) that binds PDL1, where the AB2 is attached to a maskingmoiety (MM2) such that coupling of the MM2 reduces the ability of theAB2 to bind PDL1. In some embodiments, the non-immune effector cellengaging antibody is a cancer targeting antibody. In some embodimentsthe non-immune cell effector antibody is an IgG. In some embodiments theimmune effector cell engaging antibody is a scFv. In some embodimentsthe PDL1-targeting antibody (e.g., non-immune cell effector antibody) isan IgG and the immune effector cell engaging antibody is a scFv. In someembodiments, the immune effector cell is a leukocyte. In someembodiments, the immune effector cell is a T cell. In some embodiments,the immune effector cell is a NK cell. In some embodiments, the immuneeffector cell is a myeloid mononuclear cell.

In some embodiments, T-cell engaging multispecific activatableantibodies of the disclosure include a PDL1-targeting antibody orantigen-binding fragment thereof and a T-cell engaging antibody orantigen-binding portion thereof, where at least one of thePDL1-targeting antibody or antigen-binding fragment thereof and/or theT-cell engaging antibody or antigen-binding portion thereof is masked.In some embodiments, the T-cell engaging antibody or antigen bindingfragment thereof includes a first antibody or antigen-binding fragmentthereof (AB1) that binds a first, T-cell engaging target, where the AB1is attached to a masking moiety (MM1) such that coupling of the MM1reduces the ability of the AB1 to bind the first target. In someembodiments, the targeting antibody or antigen-binding fragment thereofincludes a second antibody or fragment thereof that includes a secondantibody or antigen-binding fragment thereof (AB2) that binds PDL1,where the AB2 is attached to a masking moiety (MM2) such that couplingof the MM2 reduces the ability of the AB2 to bind PDL1. In someembodiments, the T-cell engaging antibody or antigen binding fragmentthereof includes a first antibody or antigen-binding fragment thereof(AB1) that binds a first, T-cell engaging target, where the AB1 isattached to a masking moiety (MM1) such that coupling of the MM1 reducesthe ability of the AB1 to bind the first target, and the targetingantibody or antigen-binding fragment thereof includes a second antibodyor fragment thereof that includes a second antibody or antigen-bindingfragment thereof (AB2) that binds PDL1, where the AB2 is attached to amasking moiety (MM2) such that coupling of the MM2 reduces the abilityof the AB2 to bind PDL1.

In some embodiments of an immune effector cell engaging multispecificactivatable antibody, one antigen is PDL1, and another antigen istypically a stimulatory or inhibitory receptor present on the surface ofa T-cell, natural killer (NK) cell, myeloid mononuclear cell,macrophage, and/or other immune effector cell, such as, but not limitedto, B7-H4, BTLA, CD3, CD4, CD8, CD16a, CD25, CD27, CD28, CD32, CD56,CD137, CTLA-4, GITR, HVEM, ICOS, LAG3, NKG2D, OX40, PD1, TIGIT, TIM3, orVISTA. In some embodiments, the antigen is a stimulatory receptorpresent on the surface of a T cell or NK cell; examples of suchstimulatory receptors include, but are not limited to, CD3, CD27, CD28,CD137 (also referred to as 4-1BB), GITR, HVEM, ICOS, NKG2D, and OX40. Insome embodiments, the antigen is an inhibitory receptor present on thesurface of a T-cell; examples of such inhibitory receptors include, butare not limited to, BTLA, CTLA-4, LAG3, PD1, TIGIT, TIM3, andNK-expressed KIRs. The antibody domain conferring specificity to theT-cell surface antigen may also be substituted by a ligand or liganddomain that binds to a T-cell receptor, a NK-cell receptor, a macrophagereceptor, and/or other immune effector cell receptor, such as, but notlimited to, B7-1, B7-2, B7H3, PDL1, PDL2, or TNFSF9.

In some embodiments, the T-cell engaging multispecific activatableantibody includes an anti-CD3 epsilon (CD3ε, also referred to herein asCD3ε and CD3) scFv and a targeting antibody or antigen-binding fragmentthereof, where at least one of the anti-CD3ε scFv and/or the targetingantibody or antigen-binding portion thereof is masked. In someembodiments, the CD3ε scFv includes a first antibody or antigen-bindingfragment thereof (AB1) that binds CD3ε, where the AB1 is attached to amasking moiety (MM1) such that coupling of the MM1 reduces the abilityof the AB1 to bind CD3ε. In some embodiments, the targeting antibody orantigen-binding fragment thereof includes a second antibody or fragmentthereof that includes a second antibody or antigen-binding fragmentthereof (AB2) that binds PDL1, where the AB2 is attached to a maskingmoiety (MM2) such that coupling of the MM2 reduces the ability of theAB2 to bind PDL1. In some embodiments, the CD3ε scFv includes a firstantibody or antigen-binding fragment thereof (AB1) that binds CD3ε,where the AB1 is attached to a masking moiety (MM1) such that couplingof the MM1 reduces the ability of the AB1 to bind CD3ε, and thetargeting antibody or antigen-binding fragment thereof includes a secondantibody or fragment thereof that includes a second antibody orantigen-binding fragment thereof (AB2) that binds PDL1, where the AB2 isattached to a masking moiety (MM2) such that coupling of the MM2 reducesthe ability of the AB2 to bind PDL1.

In some embodiments, the multi-antigen targeting antibodies and/ormulti-antigen targeting activatable antibodies include at least a firstantibody or antigen-binding fragment thereof that binds a first targetand/or first epitope and a second antibody or antigen-binding fragmentthereof that binds a second target and/or a second epitope. In someembodiments, the multi-antigen targeting antibodies and/or multi-antigentargeting activatable antibodies bind two or more different targets. Insome embodiments, the multi-antigen targeting antibodies and/ormulti-antigen targeting activatable antibodies bind two or moredifferent epitopes on the same target. In some embodiments, themulti-antigen targeting antibodies and/or multi-antigen targetingactivatable antibodies bind a combination of two or more differenttargets and two or more different epitopes on the same target.

In some embodiments, a multispecific activatable antibody comprising anIgG has the IgG variable domains masked. In some embodiments, amultispecific activatable antibody comprising a scFv has the scFvdomains masked. In some embodiments, a multispecific activatableantibody has both IgG variable domains and scFv domains, where at leastone of the IgG variable domains is coupled to a masking moiety. In someembodiments, a multispecific activatable antibody has both IgG variabledomains and scFv domains, where at least one of the scFv domains iscoupled to a masking moiety. In some embodiments, a multispecificactivatable antibody has both IgG variable domains and scFv domains,where at least one of the IgG variable domains is coupled to a maskingmoiety and at least one of the scFv domains is coupled to a maskingmoiety. In some embodiments, a multispecific activatable antibody hasboth IgG variable domains and scFv domains, where each of the IgGvariable domains and the scFv domains is coupled to its own maskingmoiety. In some embodiments, one antibody domain of a multispecificactivatable antibody has specificity for a target antigen and anotherantibody domain has specificity for a T-cell surface antigen. In someembodiments, one antibody domain of a multispecific activatable antibodyhas specificity for a target antigen and another antibody domain hasspecificity for another target antigen. In some embodiments, oneantibody domain of a multispecific activatable antibody has specificityfor an epitope of a target antigen and another antibody domain hasspecificity for another epitope of the target antigen.

In a multispecific activatable antibody, a scFv can be fused to thecarboxyl terminus of the heavy chain of an IgG activatable antibody, tothe carboxyl terminus of the light chain of an IgG activatable antibody,or to the carboxyl termini of both the heavy and light chains of an IgGactivatable antibody. In a multispecific activatable antibody, a scFvcan be fused to the amino terminus of the heavy chain of an IgGactivatable antibody, to the amino terminus of the light chain of an IgGactivatable antibody, or to the amino termini of both the heavy andlight chains of an IgG activatable antibody. In a multispecificactivatable antibody, a scFv can be fused to any combination of one ormore carboxyl termini and one or more amino termini of an IgGactivatable antibody. In some embodiments, a masking moiety (MM) linkedto a cleavable moiety (CM) is attached to and masks an antigen bindingdomain of the IgG. In some embodiments, a masking moiety (MM) linked toa cleavable moiety (CM) is attached to and masks an antigen bindingdomain of at least one scFv. In some embodiments, a masking moiety (MM)linked to a cleavable moiety (CM) is attached to and masks an antigenbinding domain of an IgG and a masking moiety (MM) linked to a cleavablemoiety (CM) is attached to and masks an antigen binding domain of atleast one scFv.

The disclosure provides examples of multi specific activatable antibodystructures which include, but are not limited to, the following:(VL-CL)₂:(VH-CH1-CH2-CH3-L4-VH*-L3-VL*-L2-CM-L1-MM)₂;(VL-CL)₂:(VH-CH1-CH2-CH3-L4-VL*-L3-VH*-L2-CM-L1-MM)₂;(MM-L1-CM-L2-VL-CL)₂:(VH-CH1-CH2-CH3-L4-VH*-L3-VL*)₂(MM-L1-CM-L2-VL-CL)₂:(VH-CH1-CH2-CH3-L4-VL*-L3-VH*)₂;(VL-CL)₂:(MM-L1-CM-L2-VL*-L3-VH*-L4-VH-CH1-CH2-CH3)₂;(VL-CL)₂:(MM-L1-CM-L2-VH*-L3-VL*-L4-VH-CH1-CH2-CH3)₂;(MM-L1-CM-L2-VL-CL)₂:(VL*-L3-VH*-L4-VH-CH1-CH2-CH3)₂;(MM-L1-CM-L2-VL-CL)₂:(VH*-L3-VL*-L4-VH-CH1-CH2-CH3)₂;(VL-CL-L4-VH*-L3-VL*-L2-CM-L1-MM)₂:(VH-CH1-CH2-CH3)₂;(VL-CL-L4-VL*-L3-VH*-L2-CM-L1-MM)₂:(VH-CH1-CH2-CH3)₂;(MM-L1-CM-L2-VL*-L3-VH*-L4-VL-CL)₂:(VH-CH1-CH2-CH3)₂;(MM-L1-CM-L2-VH*-L3-VL*-L4-VL-CL)₂:(VH-CH1-CH2-CH3)₂;(VL-CL-L4-VH*-L3-VL*-L2-CM-L1-MM)₂:(MM-L-CM-L2-VL*-L3-VH*-L4-VH-CH1-CH2-CH3)₂;(VL-CL-L4-VH*-L3-VL*-L2-CM-L1-MM)₂:(MM-L1-CM-L2-VH*-L3-VL*-L4-VH-CH1-CH2-CH3)₂;(VL-CL-L4-VL*-L3-VH*-L2-CM-L1-MM)₂:(MM-L1-CM-L2-VL*-L3-VH*-L4-VH-CH1-CH2-CH3)₂;(VL-CL-L4-VL*-L3-VH*-L2-CM-L1-MM)₂:(MM-L1-CM-L2-VH*-L3-VL*-L4-VH-CH1-CH2-CH3)₂; (VL-CL-L4-VH*-L3-VL*)₂:(MM-L1-CM-L2-VL*-L3-VH*-L4-VH-CH1-CH2-CH3)₂; (VL-CL-L4-VH*-L3-VL*)₂:(MM-L1-CM-L2-VH*-L3-VL*-L4-VH-CH1-CH2-CH3)₂; (VL-CL-L4-VL*-L3-VH*)₂:(MM-L-CM-L2-VL*-L3-VH*-L4-VH-CH1-CH2-CH3)₂; (VL-CL-L4-VL*-L3-VH*)₂:(MM-L1-CM-L2-VH*-L3-VL*-L4-VH-CH1-CH2-CH3)₂;(VL-CL-L4-VH*-L3-VL*-L2-CM-L1-MM)₂: (VL*-L3-VH*-L4-VH-CH1-CH2-CH3)₂,(VL-CL-L4-VH*-L3-VL*-L2-CM-L1-MM)₂: (VH*-L3-VL*-L4-VH-CH1-CH2-CH3)₂;(VL-CL-L4-VL*-L3-VH*-L2-CM-L1-MM)₂: (VL*-L3-VH*-L4-VH-CH1-CH2-CH3)₂; or(VL-CL-L4-VL*-L3-V1H*-L2-CM-L1-MM)₂: (VH*-L3-VL*-L4-VH-CH1-CH2-CH3)₂,wherein: VL and VH represent the light and heavy variable domains of thefirst specificity, contained in the IgG; VL* and VH* represent thevariable domains of the second specificity, contained in the scFv; L1 isa linker peptide connecting the masking moiety (MM) and the cleavablemoiety (CM); L2 is a linker peptide connecting the cleavable moiety(CM), and the antibody; L3 is a linker peptide connecting the variabledomains of the scFv; L4 is a linker peptide connecting the antibody ofthe first specificity to the antibody of the second specificity; CL isthe light-chain constant domain; and CH1, CH2, CH3 are the heavy chainconstant domains. The first and second specificities may be toward anyantigen or epitope.

In some embodiments of a T-cell engaging multispecific activatableantibody, one antigen is PDL1, and another antigen is typically astimulatory (also referred to herein as activating) or inhibitoryreceptor present on the surface of a T-cell, natural killer (NK) cell,myeloid mononuclear cell, macrophage, and/or other immune effector cell,such as, but not limited to, B7-H4, BTLA, CD3, CD4, CD8, CD16a, CD25,CD27, CD28, CD32, CD56, CD137 (also referred to as TNFRSF9), CTLA-4,GITR, HVEM, ICOS, LAG3, NKG2D, OX40, PD1, TIGIT, TIM3, or VISTA. Theantibody domain conferring specificity to the T-cell surface antigen mayalso be substituted by a ligand or ligand domain that binds to a T-cellreceptor, a NK-cell receptor, a macrophage receptor, and/or other immuneeffector cell receptor, such as, but not limited to, PDL1.

In some embodiments, the targeting antibody is an anti-PDL1 antibodydisclosed herein. In some embodiments, the targeting antibody can be inthe form an activatable antibody. In some embodiments, the scFv(s) canbe in the form of a Pro-scFv (see, e.g., WO 2009/025846, WO2010/081173).

In some embodiments, the scFv is specific for binding CD3ε, andcomprises or is derived from an antibody or fragment thereof that bindsCD3ε, e.g., CH2527, FN18, H2C, OKT3, 2C11, UCHT1, or V9. In someembodiments, the scFv is specific for binding CTLA-4 (also referred toherein as CTLA and CTLA4).

In some embodiments, the anti-CTLA-4 scFv includes the amino acidsequence:

(SEQ ID NO: 424) GGGSGGGGSGSGGGSGGGGSGGGEIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQYGSSPLTFGGGTKVEIKRSGGSTITSYNVYYTKLSSSGTQVQLVQTGGGVVQPGRSLRLSCAASGSTFSSYAMSWVRQAPGKGLEWVSAISGSGGSTYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCATNSLYWYFDLWGRGTLVTVSSAS

In some embodiments, the anti-CTLA-4 scFv includes the amino acidsequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,99% or more identical to the amino acid sequence of SEQ ID NO: 424.

In some embodiments, the anti-CD38 scFv includes the amino acidsequence:

(SEQ ID NO: 425) GGGSGGGGSGSGGGSGGGGSGGGQVQLQQSGAELARPGASVKMSCKASGYTFTRYTMHWVKQRPGQGLEWIGYINPSRGYTNYNQKFKDKATLTTDKSSSTAYMQLSSLTSEDSAVYYCARYYDDHYCLDYWGQGTTLTVSSGGGGSGGGGSGGGGSQIVLTQSPAIMSASPGEKVTMTCSASSSVSYMNWYQQKSGTSPKRWIYDTSKLASGVPAHFRGSGSGTSYSLTISGMEAEDAATYYCQQWSSN PFTFGSGTKLEINR

In some embodiments, the anti-CD3 scFv includes the amino acid sequencethat is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% ormore identical to the amino acid sequence of SEQ ID NO: 425.

In some embodiments, the scFv is specific for binding one or moreT-cells, one or more NK-cells and/or one or more macrophages. In someembodiments, the scFv is specific for binding a target selected from thegroup consisting of B7-H4, BTLA, CD3, CD4, CD8, CD16a, CD25, CD27, CD28,CD32, CD56, CD137, CTLA-4, GITR, HVEM, ICOS, LAG3, NKG2D, OX40, PD1,TIGIT, TIM3, or VISTA.

In some embodiments, the multispecific activatable antibody alsoincludes an agent conjugated to the AB. In some embodiments, the agentis a therapeutic agent. In some embodiments, the agent is anantineoplastic agent. In some embodiments, the agent is a toxin orfragment thereof. In some embodiments, the agent is conjugated to themultispecific activatable antibody via a linker. In some embodiments,the agent is conjugated to the AB via a cleavable linker. In someembodiments, the linker is a non-cleavable linker. In some embodiments,the agent is a microtubule inhibitor. In some embodiments, the agent isa nucleic acid damaging agent, such as a DNA alkylator or DNAintercalator, or other DNA damaging agent. In some embodiments, thelinker is a cleavable linker. In some embodiments, the agent is an agentselected from the group listed in Table 11. In some embodiments, theagent is a dolastatin. In some embodiments, the agent is an auristatinor derivative thereof. In some embodiments, the agent is auristatin E ora derivative thereof. In some embodiments, the agent is monomethylauristatin E (MMAE). In some embodiments, the agent is monomethylauristatin D (MMAD). In some embodiments, the agent is a maytansinoid ormaytansinoid derivative. In some embodiments, the agent is DM1 or DM4.In some embodiments, the agent is a duocarmycin or derivative thereof.In some embodiments, the agent is a calicheamicin or derivative thereof.In some embodiments, the agent is a pyrrolobenzodiazepine. In someembodiments, the agent is a pyrrolobenzodiazepine dimer.

In some embodiments, the multispecific activatable antibody alsoincludes a detectable moiety. In some embodiments, the detectable moietyis a diagnostic agent.

In some embodiments, the multispecific activatable antibody naturallycontains one or more disulfide bonds. In some embodiments, themultispecific activatable antibody can be engineered to include one ormore disulfide bonds.

The disclosure also provides an isolated nucleic acid molecule encodinga multispecific activatable antibody described herein, as well asvectors that include these isolated nucleic acid sequences. Thedisclosure provides methods of producing a multispecific activatableantibody by culturing a cell under conditions that lead to expression ofthe activatable antibody, wherein the cell comprises such a nucleic acidmolecule. In some embodiments, the cell comprises such a vector.

The disclosure also provides a method of manufacturing multispecificactivatable antibodies of the disclosure by (a) culturing a cellcomprising a nucleic acid construct that encodes the multispecificactivatable antibody under conditions that lead to expression of themultispecific activatable, and (b) recovering the multispecificactivatable antibody. Suitable AB, MM, and/or CM include any of the AB,MM, and/or CM disclosed herein.

The disclosure also provides multispecific activatable antibodies and/ormultispecific activatable antibody compositions that include at least afirst antibody or antigen-binding fragment thereof (AB1) thatspecifically binds a first target or first epitope and a second antibodyor antigen-biding fragment thereof (AB2) that binds a second target or asecond epitope, where at least AB1 is coupled or otherwise attached to amasking moiety (MM1), such that coupling of the MM1 reduces the abilityof AB1 to bind its target. In some embodiments, the MM1 is coupled toAB1 via a first cleavable moiety (CM1) sequence that includes asubstrate for a protease, for example, a protease that is co-localizedwith the target of AB1 at a treatment site or a diagnostic site in asubject. The multispecific activatable antibodies provided herein arestable in circulation, activated at intended sites of therapy and/ordiagnosis but not in normal, i.e., healthy tissue, and, when activated,exhibit binding to the target of AB1 that is at least comparable to thecorresponding, unmodified multispecific antibody. Suitable AB, MM,and/or CM include any of the AB, MM, and/or CM disclosed herein.

The disclosure also provides compositions and methods that include amultispecific activatable antibody that includes at least a firstantibody or antibody fragment (AB1) that specifically binds a target anda second antibody or antibody fragment (AB2), where at least the firstAB in the multispecific activatable antibody is coupled to a maskingmoiety (MM1) that decreases the ability of AB1 to bind its target. Insome embodiments, each AB is coupled to a MM that decreases the abilityof its corresponding AB to each target. For example, in bispecificactivatable antibody embodiments, AB1 is coupled to a first maskingmoiety (MM1) that decreases the ability of AB1 to bind its target, andAB2 is coupled to a second masking moiety (MM2) that decreases theability of AB2 to bind its target. In some embodiments, themultispecific activatable antibody comprises more than two AB regions;in such embodiments, AB1 is coupled to a first masking moiety (MM1) thatdecreases the ability of AB1 to bind its target, AB2 is coupled to asecond masking moiety (MM2) that decreases the ability of AB2 to bindits target, AB3 is coupled to a third masking moiety (MM3) thatdecreases the ability of AB3 to bind its target, and so on for each ABin the multispecific activatable antibody. Suitable AB, MM, and/or CMinclude any of the AB, MM, and/or CM disclosed herein.

In some embodiments, the multispecific activatable antibody furtherincludes at least one cleavable moiety (CM) that is a substrate for aprotease, where the CM links a MM to an AB. For example, in someembodiments, the multispecific activatable antibody includes at least afirst antibody or antibody fragment (AB1) that specifically binds atarget and a second antibody or antibody fragment (AB2), where at leastthe first AB in the multispecific activatable antibody is coupled via afirst cleavable moiety (CM1) to a masking moiety (MM1) that decreasesthe ability of AB1 to bind its target. In some bispecific activatableantibody embodiments, AB1 is coupled via CM1 to MM1, and AB2 is coupledvia a second cleavable moiety (CM2) to a second masking moiety (MM2)that decreases the ability of AB2 to bind its target. In someembodiments, the multispecific activatable antibody comprises more thantwo AB regions; in some of these embodiments, AB1 is coupled via CM1 toMM1, AB2 is coupled via CM2 to MM2, and AB3 is coupled via a thirdcleavable moiety (CM3) to a third masking moiety (MM3) that decreasesthe ability of AB3 to bind its target, and so on for each AB in themultispecific activatable antibody. Suitable AB, MM, and/or CM includeany of the AB, MM, and/or CM disclosed herein.

Activatable Antibodies Having Non-Binding Steric Moieties or BindingPartners for Non-Binding Steric Moieties

The disclosure also provides activatable antibodies that includenon-binding steric moieties (NB) or binding partners (BP) fornon-binding steric moieties, where the BP recruits or otherwise attractsthe NB to the activatable antibody. The activatable antibodies providedherein include, for example, an activatable antibody that includes anon-binding steric moiety (NB), a cleavable linker (CL) and antibody orantibody fragment (AB) that binds a target; an activatable antibody thatincludes a binding partner for a non-binding steric moiety (BP), a CLand an AB; and an activatable antibody that includes a BP to which an NBhas been recruited, a CL and an AB that binds the target. Activatableantibodies in which the NB is covalently linked to the CL and AB of theactivatable antibody or is associated by interaction with a BP that iscovalently linked to the CL and AB of the activatable antibody arereferred to herein as “NB-containing activatable antibodies.” Byactivatable or switchable is meant that the activatable antibodyexhibits a first level of binding to a target when the activatableantibody is in an inhibited, masked or uncleaved state (i.e., a firstconformation), and a second level of binding to the target when theactivatable antibody is in an uninhibited, unmasked and/or cleaved state(i.e., a second conformation, i.e., activated antibody), where thesecond level of target binding is greater than the first level of targetbinding. The activatable antibody compositions can exhibit increasedbioavailability and more favorable biodistribution compared toconventional antibody therapeutics.

In some embodiments, activatable antibodies provide for reduced toxicityand/or adverse side effects that could otherwise result from binding ofthe at non-treatment sites and/or non-diagnostic sites if the AB werenot masked or otherwise inhibited from binding to such a site.

Anti-PDL1 activatable antibodies that include a non-binding stericmoiety (NB) can be made using the methods set forth in PCT PublicationNo. WO 2013/192546, the contents of which are hereby incorporated byreference in their entirety.

Use of Antibodies, Conjugated Antibodies, Activatable Antibodies, andConjugated Activatable Antibodies

It will be appreciated that administration of therapeutic entities inaccordance with the disclosure will be administered with suitablecarriers, excipients, and other agents that are incorporated intoformulations to provide improved transfer, delivery, tolerance, and thelike. A multitude of appropriate formulations can be found in theformulary known to all pharmaceutical chemists: Remington'sPharmaceutical Sciences (15th ed, Mack Publishing Company, Easton, Pa.(1975)), particularly Chapter 87 by Blaug, Seymour, therein. Theseformulations include, for example, powders, pastes, ointments, jellies,waxes, oils, lipids, lipid (cationic or anionic) containing vesicles(such as Lipofectin), DNA conjugates, anhydrous absorption pastes,oil-in-water and water-in-oil emulsions, emulsions carbowax(polyethylene glycols of various molecular weights), semi-solid gels,and semi-solid mixtures containing carbowax. Any of the foregoingmixtures may be appropriate in treatments and therapies in accordancewith the present disclosure, provided that the active ingredient in theformulation is not inactivated by the formulation and the formulation isphysiologically compatible and tolerable with the route ofadministration. See also Baldrick P. “Pharmaceutical excipientdevelopment: the need for preclinical guidance.” Regul. ToxicolPharmacol. 32(2):210-8 (2000), Wang W. “Lyophilization and developmentof solid protein pharmaceuticals.” Int. J. Pharm. 203(1-2): 1-60 (2000),Charman W N “Lipids, lipophilic drugs, and oral drug delivery-someemerging concepts.” J Pharm Sci. 89(8):967-78 (2000), Powell et al.“Compendium of excipients for parenteral formulations” PDA J Pharm SciTechnol. 52:238-311 (1998) and the citations therein for additionalinformation related to formulations, excipients and carriers well knownto pharmaceutical chemists.

Therapeutic formulations of the disclosure, which include an anti-PDL1antibody and/or activatable anti-PDL1 antibody, such as by way ofnon-limiting example, an antibody, a conjugated antibody, an activatableantibody and/or a conjugated activatable antibody, are used to prevent,treat or otherwise ameliorate a disease or disorder associated withaberrant target expression and/or activity. For example, therapeuticformulations of the disclosure, which include an antibody, a conjugatedantibody, an activatable antibody and/or a conjugated activatableantibody, are used to treat or otherwise ameliorate a cancer or otherneoplastic condition, inflammation, an inflammatory disorder, and/or anautoimmune disease. In some embodiments, the cancer is a solid tumor ora hematologic malignancy where the target is expressed. In someembodiments, the cancer is a solid tumor where the target is expressed.In some embodiments, the cancer is a hematologic malignancy where thetarget is expressed. In some embodiments, the target is expressed onparenchyma (e.g., in cancer, the portion of an organ or tissue thatoften carries out function(s) of the organ or tissue). In someembodiments, the target is expressed on a cell, tissue, or organ. Insome embodiments, the target is expressed on stroma (i.e., theconnective supportive framework of a cell, tissue, or organ). In someembodiments, the target is expressed on an osteoblast. In someembodiments, the target is expressed on the endothelium (vasculature).In some embodiments, the target is expressed on a cancer stem cell. Insome embodiments, the agent to which the antibody and/or the activatableantibody is conjugated is a microtubule inhibitor. In some embodiments,the agent to which the antibody and/or the activatable antibody isconjugated is a nucleic acid damaging agent.

Efficaciousness of prevention, amelioration or treatment is determinedin association with any known method for diagnosing or treating thedisease or disorder associated with target expression and/or activity,such as, for example, aberrant target expression and/or activity.Prolonging the survival of a subject or otherwise delaying theprogression of the disease or disorder associated with target expressionand/or activity, e.g., aberrant target expression and/or activity, in asubject indicates that the antibody, conjugated antibody, activatableantibody and/or conjugated activatable antibody confers a clinicalbenefit.

An antibody, a conjugated antibody, an activatable antibody and/or aconjugated activatable antibody can be administered in the form ofpharmaceutical compositions. Principles and considerations involved inpreparing such compositions, as well as guidance in the choice ofcomponents are provided, for example, in Remington: The Science AndPractice Of Pharmacy 19th ed. (Alfonso R. Gennaro, et al., editors) MackPub. Co., Easton, Pa.: 1995; Drug Absorption Enhancement: Concepts,Possibilities, Limitations, And Trends, Harwood Academic Publishers,Langhorne, Pa., 1994; and Peptide And Protein Drug Delivery (Advances InParenteral Sciences, Vol. 4), 1991, M. Dekker, New York.

In some embodiments where antibody fragments are used, the smallestfragment that specifically binds to the binding domain of the targetprotein is selected. For example, based upon the variable-regionsequences of an antibody, peptide molecules can be designed that retainthe ability to bind the target protein sequence. Such peptides can besynthesized chemically and/or produced by recombinant DNA technology.(See, e.g., Marasco et al., Proc. Natl. Acad. Sci. USA, 90: 7889-7893(1993)). The formulation can also contain more than one active compoundsas necessary for the particular indication being treated, for example,in some embodiments, those with complementary activities that do notadversely affect each other. In some embodiments, or in addition, thecomposition can comprise an agent that enhances its function, such as,for example, a cytotoxic agent, cytokine, chemotherapeutic agent, orgrowth-inhibitory agent. Such molecules are suitably present incombination in amounts that are effective for the purpose intended.

The active ingredients can also be entrapped in microcapsules prepared,for example, by coacervation techniques or by interfacialpolymerization, for example, hydroxymethylcellulose orgelatin-microcapsules and poly-(methyl methacrylate) microcapsules,respectively, in colloidal drug delivery systems (for example,liposomes, albumin microspheres, microemulsions, nano-particles, andnanocapsules) or in macroemulsions.

The formulations to be used for in vivo administration must be sterile.This is readily accomplished by filtration through sterile filtrationmembranes.

Sustained-release preparations can be prepared. Suitable examples ofsustained-release preparations include semipermeable matrices of solidhydrophobic polymers containing the antibody, which matrices are in theform of shaped articles, e.g., films, or microcapsules. Examples ofsustained-release matrices include polyesters, hydrogels (for example,poly(2-hydroxyethyl-methacrylate), or poly(vinylalcohol)), polylactides(U.S. Pat. No. 3,773,919), copolymers of L-glutamic acid and γethyl-L-glutamate, non-degradable ethylene-vinyl acetate, degradablelactic acid-glycolic acid copolymers such as the LUPRON DEPOT™(injectable microspheres composed of lactic acid-glycolic acid copolymerand leuprolide acetate), and poly-D-(−)-3-hydroxybutyric acid. Whilepolymers such as ethylene-vinyl acetate and lactic acid-glycolic acidenable release of molecules for over 100 days, certain hydrogels releaseproteins for shorter time periods.

In some embodiments, the antibody, the conjugated antibody, activatableantibody and/or conjugated activatable antibody contains a detectablelabel. An intact antibody, or a fragment thereof (e.g., Fab, scFv, orF(ab)₂) is used. The term “labeled”, with regard to the probe orantibody, is intended to encompass direct labeling of the probe orantibody by coupling (i.e., physically linking) a detectable substanceto the probe or antibody, as well as indirect labeling of the probe orantibody by reactivity with another reagent that is directly labeled.Examples of indirect labeling include detection of a primary antibodyusing a fluorescently-labeled secondary antibody and end-labeling of aDNA probe with biotin such that it can be detected withfluorescently-labeled streptavidin. The term “biological sample” isintended to include tissues, cells and biological fluids isolated from asubject, as well as tissues, cells and fluids present within a subject.Included within the usage of the term “biological sample”, therefore, isblood and a fraction or component of blood including blood serum, bloodplasma, or lymph. That is, the detection method of the disclosure can beused to detect an analyte mRNA, protein, or genomic DNA in a biologicalsample in vitro as well as in vivo. For example, in vitro techniques fordetection of an analyte mRNA include Northern hybridizations and in situhybridizations. In vitro techniques for detection of an analyte proteininclude enzyme linked immunosorbent assays (ELISAs), Western blots,immunoprecipitations, immunochemical staining, and immunofluorescence.In vitro techniques for detection of an analyte genomic DNA includeSouthern hybridizations. Procedures for conducting immunoassays aredescribed, for example in “ELISA: Theory and Practice: Methods inMolecular Biology”, Vol. 42, J. R. Crowther (Ed.) Human Press, Totowa,N.J., 1995; “Immunoassay”, E. Diamandis and T. Christopoulus, AcademicPress, Inc., San Diego, Calif., 1996; and “Practice and Theory of EnzymeImmunoassays”, P. Tijssen, Elsevier Science Publishers, Amsterdam, 1985.Furthermore, in vivo techniques for detection of an analyte proteininclude introducing into a subject a labeled anti-analyte proteinantibody. For example, the antibody can be labeled with a radioactivemarker whose presence and location in a subject can be detected bystandard imaging techniques.

The antibodies, conjugated antibodies, activatable antibodies and/orconjugated activatable antibodies of the disclosure are also useful in avariety of diagnostic and prophylactic formulations. In one embodiment,an antibody, a conjugated antibody, an activatable antibody and/or aconjugated activatable antibody is administered to patients that are atrisk of developing one or more of the aforementioned disorders. Apatient's or organ's predisposition to one or more of the aforementioneddisorders can be determined using genotypic, serological or biochemicalmarkers.

In some embodiments of the disclosure, an antibody, a conjugatedantibody, an activatable antibody and/or a conjugated activatableantibody is administered to human individuals diagnosed with a clinicalindication associated with one or more of the aforementioned disorders.Upon diagnosis, an antibody, a conjugated antibody, an activatableantibody and/or a conjugated activatable antibody is administered tomitigate or reverse the effects of the clinical indication.

An antibody, a conjugated antibody, an activatable antibody, and/or aconjugated activatable antibody of the disclosure is also useful in thedetection of a target in patient samples and accordingly are useful asdiagnostics. For example, the antibodies and/or activatable antibodies,and conjugated versions thereof, of the disclosure are used in in vitroassays, e.g., ELISA, to detect target levels in a patient sample.

In one embodiment, an antibody, a conjugated antibody, an activatableantibody and/or a conjugated activatable antibody of the disclosure isimmobilized on a solid support (e.g., the well(s) of a microtiterplate). The immobilized antibody, conjugated antibody, activatableantibody and/or conjugated activatable antibody serves as a captureantibody for any target that may be present in a test sample. Prior tocontacting the immobilized antibody and/or activatable antibody, and/orconjugated versions thereof, with a patient sample, the solid support isrinsed and treated with a blocking agent such as milk protein or albuminto prevent nonspecific adsorption of the analyte.

Subsequently the wells are treated with a test sample suspected ofcontaining the antigen, or with a solution containing a standard amountof the antigen. Such a sample is, e.g., a serum sample from a subjectsuspected of having levels of circulating antigen considered to bediagnostic of a pathology. After rinsing away the test sample orstandard, the solid support is treated with a second antibody that isdetectably labeled. The labeled second antibody serves as a detectingantibody. The level of detectable label is measured, and theconcentration of target antigen in the test sample is determined bycomparison with a standard curve developed from the standard samples.

It will be appreciated that based on the results obtained using theantibodies and activatable antibodies of the disclosure, and conjugatedversions thereof, in an in vitro diagnostic assay, it is possible tostage a disease in a subject based on expression levels of the targetantigen. For a given disease, samples of blood are taken from subjectsdiagnosed as being at various stages in the progression of the disease,and/or at various points in the therapeutic treatment of the disease.Using a population of samples that provides statistically significantresults for each stage of progression or therapy, a range ofconcentrations of the antigen that may be considered characteristic ofeach stage is designated.

An antibody, a conjugated antibody, an activatable antibody and/or aconjugated activatable antibody can also be used in diagnostic and/orimaging methods. In some embodiments, such methods are in vitro methods.In some embodiments, such methods are in vivo methods. In someembodiments, such methods are in situ methods. In some embodiments, suchmethods are ex vivo methods. For example, activatable antibodies havingan enzymatically cleavable CM can be used to detect the presence orabsence of an enzyme that is capable of cleaving the CM. Suchactivatable antibodies can be used in diagnostics, which can include invivo detection (e.g., qualitative or quantitative) of enzyme activity(or, in some embodiments, an environment of increased reductionpotential such as that which can provide for reduction of a disulfidebond) through measured accumulation of activated antibodies (i.e.,antibodies resulting from cleavage of an activatable antibody) in agiven cell or tissue of a given host organism. Such accumulation ofactivated antibodies indicates not only that the tissue expressesenzymatic activity (or an increased reduction potential depending on thenature of the CM) but also that the tissue expresses target to which theactivated antibody binds.

For example, the CM can be selected to be substrate for at least oneprotease found at the site of a tumor, at the site of a viral orbacterial infection at a biologically confined site (e.g., such as in anabscess, in an organ, and the like), and the like. The AB can be onethat binds a target antigen. Using methods as disclosed herein, or whenappropriate, methods familiar to one skilled in the art, a detectablelabel (e.g., a fluorescent label or radioactive label or radiotracer)can be conjugated to an AB or other region of an antibody and/oractivatable antibody. Suitable detectable labels are discussed in thecontext of the above screening methods and additional specific examplesare provided below. Using an AB specific to a protein or peptide of thedisease state, along with at least one protease whose activity iselevated in the disease tissue of interest, activatable antibodies willexhibit an increased rate of binding to disease tissue relative totissues where the CM specific enzyme is not present at a detectablelevel or is present at a lower level than in disease tissue or isinactive (e.g., in zymogen form or in complex with an inhibitor). Sincesmall proteins and peptides are rapidly cleared from the blood by therenal filtration system, and because the enzyme specific for the CM isnot present at a detectable level (or is present at lower levels innon-disease tissues or is present in inactive conformation),accumulation of activated antibodies in the disease tissue is enhancedrelative to non-disease tissues.

In another example, activatable antibodies can be used to detect thepresence or absence of a cleaving agent in a sample. For example, wherethe activatable antibodies contain a CM susceptible to cleavage by anenzyme, the activatable antibodies can be used to detect (eitherqualitatively or quantitatively) the presence of an enzyme in thesample. In another example, where the activatable antibodies contain aCM susceptible to cleavage by reducing agent, the activatable antibodiescan be used to detect (either qualitatively or quantitatively) thepresence of reducing conditions in a sample. To facilitate analysis inthese methods, the activatable antibodies can be detectably labeled, andcan be bound to a support (e.g., a solid support, such as a slide orbead). The detectable label can be positioned on a portion of theactivatable antibody that is not released following cleavage, forexample, the detectable label can be a quenched fluorescent label orother label that is not detectable until cleavage has occurred. Theassay can be conducted by, for example, contacting the immobilized,detectably labeled activatable antibodies with a sample suspected ofcontaining an enzyme and/or reducing agent for a time sufficient forcleavage to occur, then washing to remove excess sample andcontaminants. The presence or absence of the cleaving agent (e.g.,enzyme or reducing agent) in the sample is then assessed by a change indetectable signal of the activatable antibodies prior to contacting withthe sample e.g., the presence of and/or an increase in detectable signaldue to cleavage of the activatable antibody by the cleaving agent in thesample.

Such detection methods can be adapted to also provide for detection ofthe presence or absence of a target that is capable of binding the AB ofthe activatable antibodies when cleaved. Thus, the assays can be adaptedto assess the presence or absence of a cleaving agent and the presenceor absence of a target of interest. The presence or absence of thecleaving agent can be detected by the presence of and/or an increase indetectable label of the activatable antibodies as described above, andthe presence or absence of the target can be detected by detection of atarget-AB complex e.g., by use of a detectably labeled anti-targetantibody.

Activatable antibodies are also useful in in situ imaging for thevalidation of activatable antibody activation, e.g., by proteasecleavage, and binding to a particular target. In situ imaging is atechnique that enables localization of proteolytic activity and targetin biological samples such as cell cultures or tissue sections. Usingthis technique, it is possible to confirm both binding to a given targetand proteolytic activity based on the presence of a detectable label(e.g., a fluorescent label).

These techniques are useful with any frozen cells or tissue derived froma disease site (e.g. tumor tissue) or healthy tissues. These techniquesare also useful with fresh cell or tissue samples.

In these techniques, an activatable antibody is labeled with adetectable label. The detectable label may be a fluorescent dye, (e.g. afluorophore, Fluorescein Isothiocyanate (FITC), Rhodamine Isothiocyanate(TRITC), an Alexa Fluor® label), a near infrared (NIR) dye (e.g., Qdot®nanocrystals), a colloidal metal, a hapten, a radioactive marker, biotinand an amplification reagent such as streptavidin, or an enzyme (e.g.horseradish peroxidase or alkaline phosphatase).

Detection of the label in a sample that has been incubated with thelabeled, activatable antibody indicates that the sample contains thetarget and contains a protease that is specific for the CM of theactivatable antibody. In some embodiments, the presence of the proteasecan be confirmed using broad spectrum protease inhibitors such as thosedescribed herein, and/or by using an agent that is specific for theprotease, for example, an antibody such as A11, which is specific forthe protease matriptase and inhibits the proteolytic activity ofmatriptase; see e.g., International Publication Number WO 2010/129609,published 11 Nov. 2010. The same approach of using broad spectrumprotease inhibitors such as those described herein, and/or by using amore selective inhibitory agent can be used to identify a protease thatis specific for the CM of the activatable antibody. In some embodiments,the presence of the target can be confirmed using an agent that isspecific for the target, e.g., another antibody, or the detectable labelcan be competed with unlabeled target. In some embodiments, unlabeledactivatable antibody could be used, with detection by a labeledsecondary antibody or more complex detection system.

Similar techniques are also useful for in vivo imaging where detectionof the fluorescent signal in a subject, e.g., a mammal, including ahuman, indicates that the disease site contains the target and containsa protease that is specific for the CM of the activatable antibody.

These techniques are also useful in kits and/or as reagents for thedetection, identification or characterization of protease activity in avariety of cells, tissues, and organisms based on the protease-specificCM in the activatable antibody.

The disclosure provides methods of using the antibodies and/oractivatable antibodies in a variety of diagnostic and/or prophylacticindications. For example, the disclosure provides methods of detectingpresence or absence of a cleaving agent and a target of interest in asubject or a sample by (i) contacting a subject or sample with anactivatable antibody, wherein the activatable antibody comprises amasking moiety (MM), a cleavable moiety (CM) that is cleaved by thecleaving agent, e.g., a protease, and an antigen binding domain orfragment thereof (AB) that specifically binds the target of interest,wherein the activatable antibody in an uncleaved, non-activated statecomprises a structural arrangement from N-terminus to C-terminus asfollows: MM-CM-AB or AB-CM-MM; (a) wherein the MM is a peptide thatinhibits binding of the AB to the target, and wherein the MM does nothave an amino acid sequence of a naturally occurring binding partner ofthe AB and is not a modified form of a natural binding partner of theAB; and (b) wherein, in an uncleaved, non-activated state, the MMinterferes with specific binding of the AB to the target, and in acleaved, activated state the MM does not interfere or compete withspecific binding of the AB to the target; and (ii) measuring a level ofactivated activatable antibody in the subject or sample, wherein adetectable level of activated activatable antibody in the subject orsample indicates that the cleaving agent and the target are present inthe subject or sample and wherein no detectable level of activatedactivatable antibody in the subject or sample indicates that thecleaving agent, the target or both the cleaving agent and the target areabsent and/or not sufficiently present in the subject or sample. In someembodiments, the activatable antibody is an activatable antibody towhich a therapeutic agent is conjugated. In some embodiments, theactivatable antibody is not conjugated to an agent. In some embodiments,the activatable antibody comprises a detectable label. In someembodiments, the detectable label is positioned on the AB. In someembodiments, measuring the level of activatable antibody in the subjector sample is accomplished using a secondary reagent that specificallybinds to the activated antibody, wherein the reagent comprises adetectable label. In some embodiments, the secondary reagent is anantibody comprising a detectable label.

The disclosure also provides methods of detecting presence or absence ofa cleaving agent in a subject or a sample by (i) contacting a subject orsample with an activatable antibody in the presence of a target ofinterest, e.g., the target, wherein the activatable antibody comprises amasking moiety (MM), a cleavable moiety (CM) that is cleaved by thecleaving agent, e.g., a protease, and an antigen binding domain orfragment thereof (AB) that specifically binds the target of interest,wherein the activatable antibody in an uncleaved, non-activated statecomprises a structural arrangement from N-terminus to C-terminus asfollows: MM-CM-AB or AB-CM-MM; (a) wherein the MM is a peptide thatinhibits binding of the AB to the target, and wherein the MM does nothave an amino acid sequence of a naturally occurring binding partner ofthe AB and is not a modified form of a natural binding partner of theAB; and (b) wherein, in an uncleaved, non-activated state, the MMinterferes with specific binding of the AB to the target, and in acleaved, activated state the MM does not interfere or compete withspecific binding of the AB to the target; and (ii) measuring a level ofactivated activatable antibody in the subject or sample, wherein adetectable level of activated activatable antibody in the subject orsample indicates that the cleaving agent is present in the subject orsample and wherein no detectable level of activated activatable antibodyin the subject or sample indicates that the cleaving agent is absentand/or not sufficiently present in the subject or sample. In someembodiments, the activatable antibody is an activatable antibody towhich a therapeutic agent is conjugated. In some embodiments, theactivatable antibody is not conjugated to an agent. In some embodiments,the activatable antibody comprises a detectable label. In someembodiments, the detectable label is positioned on the AB. In someembodiments, measuring the level of activatable antibody in the subjector sample is accomplished using a secondary reagent that specificallybinds to the activated antibody, wherein the reagent comprises adetectable label. In some embodiments, the secondary reagent is anantibody comprising a detectable label.

The disclosure also provides kits for use in methods of detectingpresence or absence of a cleaving agent and the target in a subject or asample, where the kits include at least an activatable antibodycomprises a masking moiety (MM), a cleavable moiety (CM) that is cleavedby the cleaving agent, e.g., a protease, and an antigen binding domainor fragment thereof (AB) that specifically binds the target of interest,wherein the activatable antibody in an uncleaved, non-activated statecomprises a structural arrangement from N-terminus to C-terminus asfollows: MM-CM-AB or AB-CM-MM; (a) wherein the MM is a peptide thatinhibits binding of the AB to the target, and wherein the MM does nothave an amino acid sequence of a naturally occurring binding partner ofthe AB and is not a modified form of a natural binding partner of theAB; and (b) wherein, in an uncleaved, non-activated state, the MMinterferes with specific binding of the AB to the target, and in acleaved, activated state the MM does not interfere or compete withspecific binding of the AB to the target; and (ii) measuring a level ofactivated activatable antibody in the subject or sample, wherein adetectable level of activated activatable antibody in the subject orsample indicates that the cleaving agent is present in the subject orsample and wherein no detectable level of activated activatable antibodyin the subject or sample indicates that the cleaving agent is absentand/or not sufficiently present in the subject or sample. In someembodiments, the activatable antibody is an activatable antibody towhich a therapeutic agent is conjugated. In some embodiments, theactivatable antibody is not conjugated to an agent. In some embodiments,the activatable antibody comprises a detectable label. In someembodiments, the detectable label is positioned on the AB. In someembodiments, measuring the level of activatable antibody in the subjector sample is accomplished using a secondary reagent that specificallybinds to the activated antibody, wherein the reagent comprises adetectable label. In some embodiments, the secondary reagent is anantibody comprising a detectable label.

The disclosure also provides methods of detecting presence or absence ofa cleaving agent in a subject or a sample by (i) contacting a subject orsample with an activatable antibody, wherein the activatable antibodycomprises a masking moiety (MM), a cleavable moiety (CM) that is cleavedby the cleaving agent, e.g., a protease, an antigen binding domain (AB)that specifically binds the target, and a detectable label, wherein theactivatable antibody in an uncleaved, non-activated state comprises astructural arrangement from N-terminus to C-terminus as follows:MM-CM-AB or AB-CM-MM; wherein the MM is a peptide that inhibits bindingof the AB to the target, and wherein the MM does not have an amino acidsequence of a naturally occurring binding partner of the AB and is not amodified form of a natural binding partner of the AB; wherein, in anuncleaved, non-activated state, the MM interferes with specific bindingof the AB to the target, and in a cleaved, activated state the MM doesnot interfere or compete with specific binding of the AB to the target;and wherein the detectable label is positioned on a portion of theactivatable antibody that is released following cleavage of the CM; and(ii) measuring a level of detectable label in the subject or sample,wherein a detectable level of the detectable label in the subject orsample indicates that the cleaving agent is absent and/or notsufficiently present in the subject or sample and wherein no detectablelevel of the detectable label in the subject or sample indicates thatthe cleaving agent is present in the subject or sample. In someembodiments, the activatable antibody is an activatable antibody towhich a therapeutic agent is conjugated. In some embodiments, theactivatable antibody is not conjugated to an agent. In some embodiments,the activatable antibody comprises a detectable label. In someembodiments, the detectable label is positioned on the AB. In someembodiments, measuring the level of activatable antibody in the subjector sample is accomplished using a secondary reagent that specificallybinds to the activated antibody, wherein the reagent comprises adetectable label. In some embodiments, the secondary reagent is anantibody comprising a detectable label.

The disclosure also provides kits for use in methods of detectingpresence or absence of a cleaving agent and the target in a subject or asample, where the kits include at least an activatable antibody and/orconjugated activatable antibody (e.g., an activatable antibody to whicha therapeutic agent is conjugated) described herein for use incontacting a subject or biological sample and means for detecting thelevel of activated activatable antibody and/or conjugated activatableantibody in the subject or biological sample, wherein a detectable levelof activated activatable antibody in the subject or biological sampleindicates that the cleaving agent and the target are present in thesubject or biological sample and wherein no detectable level ofactivated activatable antibody in the subject or biological sampleindicates that the cleaving agent, the target or both the cleaving agentand the target are absent and/or not sufficiently present in the subjector biological sample, such that the target binding and/or proteasecleavage of the activatable antibody cannot be detected in the subjector biological sample.

The disclosure also provides methods of detecting presence or absence ofa cleaving agent in a subject or a sample by (i) contacting a subject orbiological sample with an activatable antibody in the presence of thetarget, and (ii) measuring a level of activated activatable antibody inthe subject or biological sample, wherein a detectable level ofactivated activatable antibody in the subject or biological sampleindicates that the cleaving agent is present in the subject orbiological sample and wherein no detectable level of activatedactivatable antibody in the subject or biological sample indicates thatthe cleaving agent is absent and/or not sufficiently present in thesubject or biological sample at a detectable level, such that proteasecleavage of the activatable antibody cannot be detected in the subjector biological sample. Such an activatable antibody includes a maskingmoiety (MM), a cleavable moiety (CM) that is cleaved by the cleavingagent, e.g., a protease, and an antigen binding domain or fragmentthereof (AB) that specifically binds the target, wherein the activatableantibody in an uncleaved (i.e., non-activated) state comprises astructural arrangement from N-terminus to C-terminus as follows:MM-CM-AB or AB-CM-MM, (a) wherein the MM is a peptide that inhibitsbinding of the AB to the target, and wherein the MM does not have anamino acid sequence of a naturally occurring binding partner of the AB;and (b) wherein the MM of the activatable antibody in an uncleaved stateinterferes with specific binding of the AB to the target, and whereinthe MM of an activatable antibody in a cleaved (i.e., activated) statedoes not interfere or compete with specific binding of the AB to thetarget. In some embodiments, the activatable antibody is an activatableantibody to which a therapeutic agent is conjugated. In someembodiments, the activatable antibody is not conjugated to an agent. Insome embodiments, the detectable label is attached to the maskingmoiety. In some embodiments, the detectable label is attached to thecleavable moiety N-terminal to the protease cleavage site. In someembodiments, a single antigen binding site of the AB is masked. In someembodiments wherein an antibody of the disclosure has at least twoantigen binding sites, at least one antigen binding site is masked andat least one antigen binding site is not masked. In some embodiments allantigen binding sites are masked. In some embodiments, the measuringstep includes use of a secondary reagent comprising a detectable label.

The disclosure also provides kits for use in methods of detectingpresence or absence of a cleaving agent and the target in a subject or asample, where the kits include at least an activatable antibody and/orconjugated activatable antibody described herein for use in contacting asubject or biological sample with an activatable antibody in thepresence of the target, and measuring a level of activated activatableantibody in the subject or biological sample, wherein a detectable levelof activated activatable antibody in the subject or biological sampleindicates that the cleaving agent is present in the subject orbiological sample and wherein no detectable level of activatedactivatable antibody in the subject or biological sample indicates thatthe cleaving agent is absent and/or not sufficiently present in thesubject or biological sample at a detectable level, such that proteasecleavage of the activatable antibody cannot be detected in the subjector biological sample. Such an activatable antibody includes a maskingmoiety (MM), a cleavable moiety (CM) that is cleaved by the cleavingagent, e.g., a protease, and an antigen binding domain or fragmentthereof (AB) that specifically binds the target, wherein the activatableantibody in an uncleaved (i.e., non-activated) state comprises astructural arrangement from N-terminus to C-terminus as follows:MM-CM-AB or AB-CM-MM; (a) wherein the MM is a peptide that inhibitsbinding of the AB to the target, and wherein the MM does not have anamino acid sequence of a naturally occurring binding partner of the AB;and (b) wherein the MM of the activatable antibody in an uncleaved stateinterferes with specific binding of the AB to the target, and whereinthe MM of an activatable antibody in a cleaved (i.e., activated) statedoes not interfere or compete with specific binding of the AB to thetarget. In some embodiments, the activatable antibody is an activatableantibody to which a therapeutic agent is conjugated. In someembodiments, the activatable antibody is not conjugated to an agent. Insome embodiments, the detectable label is attached to the maskingmoiety. In some embodiments, the detectable label is attached to thecleavable moiety N-terminal to the protease cleavage site. In someembodiments, a single antigen binding site of the AB is masked. In someembodiments wherein an antibody of the disclosure has at least twoantigen binding sites, at least one antigen binding site is masked andat least one antigen binding site is not masked. In some embodiments allantigen binding sites are masked. In some embodiments, the measuringstep includes use of a secondary reagent comprising a detectable label.

The disclosure also provides kits for use in methods of detectingpresence or absence of a cleaving agent in a subject or a sample, wherethe kits include at least an activatable antibody and/or conjugatedactivatable antibody described herein for use in contacting a subject orbiological sample and means for detecting the level of activatedactivatable antibody and/or conjugated activatable antibody in thesubject or biological sample, wherein the activatable antibody includesa detectable label that is positioned on a portion of the activatableantibody that is released following cleavage of the CM, wherein adetectable level of activated activatable antibody in the subject orbiological sample indicates that the cleaving agent is absent and/or notsufficiently present in the subject or biological sample such that thetarget binding and/or protease cleavage of the activatable antibodycannot be detected in the subject or biological sample, and wherein nodetectable level of activated activatable antibody in the subject orbiological sample indicates that the cleaving agent is present in thesubject or biological sample at a detectable level.

The disclosure provides methods of detecting presence or absence of acleaving agent and the target in a subject or a sample by (i) contactinga subject or biological sample with an activatable antibody, wherein theactivatable antibody includes a detectable label that is positioned on aportion of the activatable antibody that is released following cleavageof the CM and (ii) measuring a level of activated activatable antibodyin the subject or biological sample, wherein a detectable level ofactivated activatable antibody in the subject or biological sampleindicates that the cleaving agent, the target or both the cleaving agentand the target are absent and/or not sufficiently present in the subjector biological sample, such that the target binding and/or proteasecleavage of the activatable antibody cannot be detected in the subjector biological sample, and wherein a reduced detectable level ofactivated activatable antibody in the subject or biological sampleindicates that the cleaving agent and the target are present in thesubject or biological sample. A reduced level of detectable label is,for example, a reduction of about 5%, about 10%, about 15%, about 20%,about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%,about 90%, about 95% and/or about 100%. Such an activatable antibodyincludes a masking moiety (MM), a cleavable moiety (CM) that is cleavedby the cleaving agent, and an antigen binding domain or fragment thereof(AB) that specifically binds the target, wherein the activatableantibody in an uncleaved (i.e., non-activated) state comprises astructural arrangement from N-terminus to C-terminus as follows:MM-CM-AB or AB-CM-MM; (a) wherein the MM is a peptide that inhibitsbinding of the AB to the target, and wherein the MM does not have anamino acid sequence of a naturally occurring binding partner of the AB;and (b) wherein the MM of the activatable antibody in an uncleaved stateinterferes with specific binding of the AB to the target, and whereinthe MM of an activatable antibody in a cleaved (i.e., activated) statedoes not interfere or compete with specific binding of the AB to thetarget. In some embodiments, the activatable antibody is an activatableantibody to which a therapeutic agent is conjugated. In someembodiments, the activatable antibody is not conjugated to an agent. Insome embodiments, the activatable antibody comprises a detectable label.In some embodiments, the detectable label is positioned on the AB. Insome embodiments, measuring the level of activatable antibody in thesubject or sample is accomplished using a secondary reagent thatspecifically binds to the activated antibody, wherein the reagentcomprises a detectable label. In some embodiments, the secondary reagentis an antibody comprising a detectable label.

The disclosure also provides kits for use in methods of detectingpresence or absence of a cleaving agent and the target in a subject or asample, where the kits include at least an activatable antibody and/orconjugated activatable antibody described herein for use in contacting asubject or biological sample and means for detecting the level ofactivated activatable antibody and/or conjugated activatable antibody inthe subject or biological sample, wherein a detectable level ofactivated activatable antibody in the subject or biological sampleindicates that the cleaving agent, the target or both the cleaving agentand the target are absent and/or not sufficiently present in the subjector biological sample, such that the target binding and/or proteasecleavage of the activatable antibody cannot be detected in the subjector biological sample, and wherein a reduced detectable level ofactivated activatable antibody in the subject or biological sampleindicates that the cleaving agent and the target are present in thesubject or biological sample. A reduced level of detectable label is,for example, a reduction of about 5%, about 10%, about 15%, about 20%,about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%,about 90%, about 95% and/or about 100%.

The disclosure also provides methods of detecting presence or absence ofa cleaving agent in a subject or a sample by (i) contacting a subject orbiological sample with an activatable antibody, wherein the activatableantibody includes a detectable label that is positioned on a portion ofthe activatable antibody that is released following cleavage of the CM;and (ii) measuring a level of detectable label in the subject orbiological sample, wherein a detectable level of the detectable label inthe subject or biological sample indicates that the cleaving agent isabsent and/or not sufficiently present in the subject or biologicalsample at a detectable level, such that protease cleavage of theactivatable antibody cannot be detected in the subject or biologicalsample, and wherein a reduced detectable level of the detectable labelin the subject or biological sample indicates that the cleaving agent ispresent in the subject or biological sample. A reduced level ofdetectable label is, for example, a reduction of about 5%, about 10%,about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%,about 80%, about 85%, about 90%, about 95% and/or about 100%. Such anactivatable antibody includes a masking moiety (MM), a cleavable moiety(CM) that is cleaved by the cleaving agent, and an antigen bindingdomain or fragment thereof (AB) that specifically binds the target,wherein the activatable antibody in an uncleaved (i.e., non-activated)state comprises a structural arrangement from N-terminus to C-terminusas follows: MM-CM-AB or AB-CM-MM; (a) wherein the MM is a peptide thatinhibits binding of the AB to the target, and wherein the MM does nothave an amino acid sequence of a naturally occurring binding partner ofthe AB; and (b) wherein the MM of the activatable antibody in anuncleaved state interferes with specific binding of the AB to thetarget, and wherein the MM of an activatable antibody in a cleaved(i.e., activated) state does not interfere or compete with specificbinding of the AB to the target. In some embodiments, the activatableantibody is an activatable antibody to which a therapeutic agent isconjugated. In some embodiments, the activatable antibody is notconjugated to an agent. In some embodiments, the activatable antibodycomprises a detectable label. In some embodiments, the detectable labelis positioned on the AB. In some embodiments, measuring the level ofactivatable antibody in the subject or sample is accomplished using asecondary reagent that specifically binds to the activated antibody,wherein the reagent comprises a detectable label. In some embodiments,the secondary reagent is an antibody comprising a detectable label.

The disclosure also provides kits for use in methods of detectingpresence or absence of a cleaving agent of interest in a subject or asample, where the kits include at least an activatable antibody and/orconjugated activatable antibody described herein for use in contacting asubject or biological sample and means for detecting the level ofactivated activatable antibody and/or conjugated activatable antibody inthe subject or biological sample, wherein the activatable antibodyincludes a detectable label that is positioned on a portion of theactivatable antibody that is released following cleavage of the CM,wherein a detectable level of the detectable label in the subject orbiological sample indicates that the cleaving agent, the target, or boththe cleaving agent and the target are absent and/or not sufficientlypresent in the subject or biological sample, such that the targetbinding and/or protease cleavage of the activatable antibody cannot bedetected in the subject or biological sample, and wherein a reduceddetectable level of the detectable label in the subject or biologicalsample indicates that the cleaving agent and the target are present inthe subject or biological sample. A reduced level of detectable labelis, for example, a reduction of about 5%, about 10%, about 15%, about20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%,about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about85%, about 90%, about 95% and/or about 100%.

In some embodiments of these methods and kits, the activatable antibodyincludes a detectable label. In some embodiments of these methods andkits, the detectable label includes an imaging agent, a contrastingagent, an enzyme, a fluorescent label, a chromophore, a dye, one or moremetal ions, or a ligand-based label. In some embodiments of thesemethods and kits, the imaging agent comprises a radioisotope. In someembodiments of these methods and kits, the radioisotope is indium ortechnetium. In some embodiments of these methods and kits, thecontrasting agent comprises iodine, gadolinium or iron oxide. In someembodiments of these methods and kits, the enzyme comprises horseradishperoxidase, alkaline phosphatase, or β-galactosidase. In someembodiments of these methods and kits, the fluorescent label comprisesyellow fluorescent protein (YFP), cyan fluorescent protein (CFP), greenfluorescent protein (GFP), modified red fluorescent protein (mRFP), redfluorescent protein tdimer2 (RFP tdimer2), HCRED, or a europiumderivative. In some embodiments of these methods and kits, theluminescent label comprises an N-methylacrydium derivative. In someembodiments of these methods, the label comprises an Alexa Fluor® label,such as Alex Fluor® 680 or Alexa Fluor® 750. In some embodiments ofthese methods and kits, the ligand-based label comprises biotin, avidin,streptavidin or one or more haptens.

In some embodiments of these methods and kits, the subject is a mammal.In some embodiments of these methods and kits, the subject is a human.In some embodiments, the subject is a non-human mammal, such as anon-human primate, companion animal (e.g., cat, dog, horse), farmanimal, work animal, or zoo animal. In some embodiments, the subject isa rodent.

In some embodiments of these methods, the method is an in vivo method.In some embodiments of these methods, the method is an in situ method.In some embodiments of these methods, the method is an ex vivo method.In some embodiments of these methods, the method is an in vitro method.

In some embodiments, in situ imaging and/or in vivo imaging are usefulin methods to identify which patients to treat. For example, in in situimaging, the activatable antibodies are used to screen patient samplesto identify those patients having the appropriate protease(s) andtarget(s) at the appropriate location, e.g., at a tumor site.

In some embodiments in situ imaging is used to identify or otherwiserefine a patient population suitable for treatment with an activatableantibody of the disclosure. For example, patients that test positive forboth the target (e.g., the target) and a protease that cleaves thesubstrate in the cleavable moiety (CM) of the activatable antibody beingtested (e.g., accumulate activated antibodies at the disease site) areidentified as suitable candidates for treatment with such an activatableantibody comprising such a CM. Likewise, patients that test negative foreither or both of the target (e.g., the target) and the protease thatcleaves the substrate in the CM in the activatable antibody being testedusing these methods might be identified as suitable candidates foranother form of therapy. In some embodiments, such patients that testnegative with respect to a first activatable antibody can be tested withother activatable antibodies comprising different CMs until a suitableactivatable antibody for treatment is identified (e.g., an activatableantibody comprising a CM that is cleaved by the patient at the site ofdisease). In some embodiments, the patient is then administered atherapeutically effective amount of the activatable antibody for whichthe patient tested positive.

In some embodiments in vivo imaging is used to identify or otherwiserefine a patient population suitable for treatment with an activatableantibody of the disclosure. For example, patients that test positive forboth the target (e.g., the target) and a protease that cleaves thesubstrate in the cleavable moiety (CM) of the activatable antibody beingtested (e.g., accumulate activated antibodies at the disease site) areidentified as suitable candidates for treatment with such an activatableantibody comprising such a CM. Likewise, patients that test negativemight be identified as suitable candidates for another form of therapy.In some embodiments, such patients that test negative with respect to afirst activatable antibody can be tested with other activatableantibodies comprising different CMs until a suitable activatableantibody for treatment is identified (e.g., an activatable antibodycomprising a CM that is cleaved by the patient at the site of disease).In some embodiments, the patient is then administered a therapeuticallyeffective amount of the activatable antibody for which the patienttested positive.

In some embodiments of the methods and kits, the method or kit is usedto identify or otherwise refine a patient population suitable fortreatment with an activatable antibody of the disclosure. For example,patients that test positive for both the target (e.g., the target) and aprotease that cleaves the substrate in the cleavable moiety (CM) of theactivatable antibody being tested in these methods are identified assuitable candidates for treatment with such an activatable antibodycomprising such a CM. Likewise, patients that test negative for both ofthe targets (e.g., the target) and the protease that cleaves thesubstrate in the CM in the activatable antibody being tested using thesemethods might be identified as suitable candidates for another form oftherapy. In some embodiments, such patients can be tested with otheractivatable antibodies until a suitable activatable antibody fortreatment is identified (e.g., an activatable antibody comprising a CMthat is cleaved by the patient at the site of disease). In someembodiments, patients that test negative for either of the target (e.g.,the target) are identified as suitable candidates for treatment withsuch an activatable antibody comprising such a CM. In some embodiments,patients that test negative for either of the target (e.g., the target)are identified as not being suitable candidates for treatment with suchan activatable antibody comprising such a CM. In some embodiments, suchpatients can be tested with other activatable antibodies until asuitable activatable antibody for treatment is identified (e.g., anactivatable antibody comprising a CM that is cleaved by the patient atthe site of disease). In some embodiments, the activatable antibody isan activatable antibody to which a therapeutic agent is conjugated. Insome embodiments, the activatable antibody is not conjugated to anagent. In some embodiments, the activatable antibody comprises adetectable label. In some embodiments, the detectable label ispositioned on the AB. In some embodiments, measuring the level ofactivatable antibody in the subject or sample is accomplished using asecondary reagent that specifically binds to the activated antibody,wherein the reagent comprises a detectable label. In some embodiments,the secondary reagent is an antibody comprising a detectable label.

In some embodiments, a method or kit is used to identify or otherwiserefine a patient population suitable for treatment with an anti-thetarget activatable antibody and/or conjugated activatable antibody(e.g., activatable antibody to which a therapeutic agent is conjugated)of the disclosure, followed by treatment by administering thatactivatable antibody and/or conjugated activatable antibody to a subjectin need thereof. For example, patients that test positive for both thetargets (e.g., the target) and a protease that cleaves the substrate inthe cleavable moiety (CM) of the activatable antibody and/or conjugatedactivatable antibody being tested in these methods are identified assuitable candidates for treatment with such antibody and/or such aconjugated activatable antibody comprising such a CM, and the patient isthen administered a therapeutically effective amount of the activatableantibody and/or conjugated activatable antibody that was tested.Likewise, patients that test negative for either or both of the target(e.g., the target) and the protease that cleaves the substrate in the CMin the activatable antibody being tested using these methods might beidentified as suitable candidates for another form of therapy. In someembodiments, such patients can be tested with other antibody and/orconjugated activatable antibody until a suitable antibody and/orconjugated activatable antibody for treatment is identified (e.g., anactivatable antibody and/or conjugated activatable antibody comprising aCM that is cleaved by the patient at the site of disease). In someembodiments, the patient is then administered a therapeuticallyeffective amount of the activatable antibody and/or conjugatedactivatable antibody for which the patient tested positive.

In some embodiments of these methods and kits, the MM is a peptidehaving a length from about 4 to 40 amino acids. In some embodiments ofthese methods and kits, the activatable antibody comprises a linkerpeptide, wherein the linker peptide is positioned between the MM and theCM. In some embodiments of these methods and kits, the activatableantibody comprises a linker peptide, where the linker peptide ispositioned between the AB and the CM. In some embodiments of thesemethods and kits, the activatable antibody comprises a first linkerpeptide (L1) and a second linker peptide (L2), wherein the first linkerpeptide is positioned between the MM and the CM and the second linkerpeptide is positioned between the AB and the CM. In some embodiments ofthese methods and kits, each of L1 and L2 is a peptide of about 1 to 20amino acids in length, and wherein each of L1 and L2 need not be thesame linker. In some embodiments of these methods and kits, one or bothof L1 and L2 comprises a glycine-serine polymer. In some embodiments ofthese methods and kits, at least one of L1 and L2 comprises an aminoacid sequence selected from the group consisting of (GS)n, (GSGGS)n (SEQID NO: 191) and (GGS)n (SEQ ID NO: 192), where n is an integer of atleast one. In some embodiments of these methods and kits, at least oneof L1 and L2 comprises an amino acid sequence having the formula (GGS)n,where n is an integer of at least one. In some embodiments of thesemethods and kits, at least one of L1 and L2 comprises an amino acidsequence selected from the group consisting of Gly-Gly-Ser-Gly (SEQ IDNO: 193), Gly-Gly-Ser-Gly-Gly (SEQ ID NO: 194), Gly-Ser-Gly-Ser-Gly (SEQID NO: 195), Gly-Ser-Gly-Gly-Gly (SEQ ID NO: 196), Gly-Gly-Gly-Ser-Gly(SEQ ID NO: 197), and Gly-Ser-Ser-Ser-Gly (SEQ ID NO: 198).

In some embodiments of these methods and kits, the AB comprises anantibody or antibody fragment sequence selected from the cross-reactiveantibody sequences presented herein. In some embodiments of thesemethods and kits, the AB comprises a Fab fragment, a scFv or a singlechain antibody (scAb).

In some embodiments of these methods and kits, the cleaving agent is aprotease that is co-localized in the subject or sample with the targetand the CM is a polypeptide that functions as a substrate for theprotease, wherein the protease cleaves the CM in the activatableantibody when the activatable antibody is exposed to the protease. Insome embodiments of these methods and kits, the CM is a polypeptide ofup to 15 amino acids in length. In some embodiments of these methods andkits, the CM is coupled to the N-terminus of the AB. In some embodimentsof these methods and kits, the CM is coupled to the C-terminus of theAB. In some embodiments of these methods and kits, the CM is coupled tothe N-terminus of a VL chain of the AB.

The antibodies, conjugated antibodies, activatable antibodies and/orconjugated activatable antibodies of the disclosure are used indiagnostic and prophylactic formulations. In one embodiment, anactivatable antibody is administered to patients that are at risk ofdeveloping one or more of the aforementioned inflammation, inflammatorydisorders, cancer or other disorders.

A patient's or organ's predisposition to one or more of theaforementioned disorders can be determined using genotypic, serologicalor biochemical markers.

In some embodiments of the disclosure, an antibody, a conjugatedantibody, an activatable antibody and/or a conjugated activatableantibody is administered to human individuals diagnosed with a clinicalindication associated with one or more of the aforementioned disorders.Upon diagnosis, an antibody, a conjugated antibody, an activatableantibody and/or a conjugated activatable antibody is administered tomitigate or reverse the effects of the clinical indication.

Antibodies, conjugated antibodies, activatable antibodies and/orconjugated activatable antibodies of the disclosure are also useful inthe detection of the target in patient samples and accordingly areuseful as diagnostics. For example, the antibodies, conjugatedantibodies, the activatable antibodies and/or conjugated activatableantibodies of the disclosure are used in in vitro assays, e.g., ELISA,to detect target levels in a patient sample.

In one embodiment, an antibody and/or activatable antibody of thedisclosure is immobilized on a solid support (e.g., the well(s) of amicrotiter plate). The immobilized antibody and/or activatable antibodyserves as a capture antibody for any target that may be present in atest sample. Prior to contacting the immobilized antibody and/oractivatable antibody with a patient sample, the solid support is rinsedand treated with a blocking agent such as milk protein or albumin toprevent nonspecific adsorption of the analyte.

Subsequently the wells are treated with a test sample suspected ofcontaining the antigen, or with a solution containing a standard amountof the antigen. Such a sample is, e.g., a serum sample from a subjectsuspected of having levels of circulating antigen considered to bediagnostic of a pathology. After rinsing away the test sample orstandard, the solid support is treated with a second antibody that isdetectably labeled. The labeled second antibody serves as a detectingantibody. The level of detectable label is measured, and theconcentration of target antigen in the test sample is determined bycomparison with a standard curve developed from the standard samples.

It will be appreciated that based on the results obtained using theantibodies and/or activatable antibodies of the disclosure in an invitro diagnostic assay, it is possible to stage a disease in a subjectbased on expression levels of the Target antigen. For a given disease,samples of blood are taken from subjects diagnosed as being at variousstages in the progression of the disease, and/or at various points inthe therapeutic treatment of the disease. Using a population of samplesthat provides statistically significant results for each stage ofprogression or therapy, a range of concentrations of the antigen thatmay be considered characteristic of each stage is designated.

Antibodies, conjugated antibodies, activatable antibodies and/orconjugated activatable antibodies can also be used in diagnostic and/orimaging methods. In some embodiments, such methods are in vitro methods.In some embodiments, such methods are in vivo methods. In someembodiments, such methods are in sit, methods. In some embodiments, suchmethods are ex vivo methods. For example, activatable antibodies havingan enzymatically cleavable CM can be used to detect the presence orabsence of an enzyme that is capable of cleaving the CM. Suchactivatable antibodies can be used in diagnostics, which can include invivo detection (e.g., qualitative or quantitative) of enzyme activity(or, in some embodiments, an environment of increased reductionpotential such as that which can provide for reduction of a disulfidebond) through measured accumulation of activated antibodies (i.e.,antibodies resulting from cleavage of an activatable antibody) in agiven cell or tissue of a given host organism. Such accumulation ofactivated antibodies indicates not only that the tissue expressesenzymatic activity (or an increased reduction potential depending on thenature of the CM) but also that the tissue expresses target to which theactivated antibody binds.

For example, the CM can be selected to be a protease substrate for aprotease found at the site of a tumor, at the site of a viral orbacterial infection at a biologically confined site (e.g., such as in anabscess, in an organ, and the like), and the like. The AB can be onethat binds a target antigen. Using methods familiar to one skilled inthe art, a detectable label (e.g., a fluorescent label or radioactivelabel or radiotracer) can be conjugated to an AB or other region of anactivatable antibody. Suitable detectable labels are discussed in thecontext of the above screening methods and additional specific examplesare provided below. Using an AB specific to a protein or peptide of thedisease state, along with a protease whose activity is elevated in thedisease tissue of interest, activatable antibodies will exhibit anincreased rate of binding to disease tissue relative to tissues wherethe CM specific enzyme is not present at a detectable level or ispresent at a lower level than in disease tissue or is inactive (e.g., inzymogen form or in complex with an inhibitor). Since small proteins andpeptides are rapidly cleared from the blood by the renal filtrationsystem, and because the enzyme specific for the CM is not present at adetectable level (or is present at lower levels in non-disease tissuesor is present in inactive conformation), accumulation of activatedantibodies in the disease tissue is enhanced relative to non-diseasetissues.

In another example, activatable antibodies can be used to detect thepresence or absence of a cleaving agent in a sample. For example, wherethe activatable antibodies contain a CM susceptible to cleavage by anenzyme, the activatable antibodies can be used to detect (eitherqualitatively or quantitatively) the presence of an enzyme in thesample. In another example, where the activatable antibodies contain aCM susceptible to cleavage by reducing agent, the activatable antibodiescan be used to detect (either qualitatively or quantitatively) thepresence of reducing conditions in a sample. To facilitate analysis inthese methods, the activatable antibodies can be detectably labeled, andcan be bound to a support (e.g., a solid support, such as a slide orbead). The detectable label can be positioned on a portion of theactivatable antibody that is not released following cleavage, forexample, the detectable label can be a quenched fluorescent label orother label that is not detectable until cleavage has occurred. Theassay can be conducted by, for example, contacting the immobilized,detectably labeled activatable antibodies with a sample suspected ofcontaining an enzyme and/or reducing agent for a time sufficient forcleavage to occur, then washing to remove excess sample andcontaminants. The presence or absence of the cleaving agent (e.g.,enzyme or reducing agent) in the sample is then assessed by a change indetectable signal of the activatable antibodies prior to contacting withthe sample e.g., the presence of and/or an increase in detectable signaldue to cleavage of the activatable antibody by the cleaving agent in thesample.

Such detection methods can be adapted to also provide for detection ofthe presence or absence of a target that is capable of binding the AB ofthe activatable antibodies when cleaved. Thus, the assays can be adaptedto assess the presence or absence of a cleaving agent and the presenceor absence of a target of interest. The presence or absence of thecleaving agent can be detected by the presence of and/or an increase indetectable label of the activatable antibodies as described above, andthe presence or absence of the target can be detected by detection of atarget-AB complex e.g., by use of a detectably labeled anti-targetantibody.

Activatable antibodies are also useful in in situ imaging for thevalidation of activatable antibody activation, e.g., by proteasecleavage, and binding to a particular target. In situ imaging is atechnique that enables localization of proteolytic activity and targetin biological samples such as cell cultures or tissue sections. Usingthis technique, it is possible to confirm both binding to a given targetand proteolytic activity based on the presence of a detectable label(e.g., a fluorescent label).

These techniques are useful with any frozen cells or tissue derived froma disease site (e.g. tumor tissue) or healthy tissues. These techniquesare also useful with fresh cell or tissue samples.

In these techniques, an activatable antibody is labeled with adetectable label. The detectable label may be a fluorescent dye, (e.g.Fluorescein Isothiocyanate (FITC), Rhodamine Isothiocyanate (TRITC), anear infrared (NIR) dye (e.g., Qdot® nanocrystals), a colloidal metal, ahapten, a radioactive marker, biotin and an amplification reagent suchas streptavidin, or an enzyme (e.g. horseradish peroxidase or alkalinephosphatase).

Detection of the label in a sample that has been incubated with thelabeled, activatable antibody indicates that the sample contains thetarget and contains a protease that is specific for the CM of theactivatable antibody. In some embodiments, the presence of the proteasecan be confirmed using broad spectrum protease inhibitors such as thosedescribed herein, and/or by using an agent that is specific for theprotease, for example, an antibody such as A11, which is specific forthe protease matriptase and inhibits the proteolytic activity ofmatriptase; see e.g., International Publication Number WO 2010/129609,published 11 Nov. 2010. The same approach of using broad spectrumprotease inhibitors such as those described herein, and/or by using amore selective inhibitory agent can be used to identify a protease orclass of proteases specific for the CM of the activatable antibody. Insome embodiments, the presence of the target can be confirmed using anagent that is specific for the target, e.g., another antibody, or thedetectable label can be competed with unlabeled target. In someembodiments, unlabeled activatable antibody could be used, withdetection by a labeled secondary antibody or more complex detectionsystem.

Similar techniques are also useful for in vivo imaging where detectionof the fluorescent signal in a subject, e.g., a mammal, including ahuman, indicates that the disease site contains the target and containsa protease that is specific for the CM of the activatable antibody.

These techniques are also useful in kits and/or as reagents for thedetection, identification or characterization of protease activity in avariety of cells, tissues, and organisms based on the protease-specificCM in the activatable antibody.

In some embodiments, in situ imaging and/or in vivo imaging are usefulin methods to identify which patients to treat. For example, in in situimaging, the activatable antibodies are used to screen patient samplesto identify those patients having the appropriate protease(s) andtarget(s) at the appropriate location, e.g., at a tumor site.

In some embodiments in situ imaging is used to identify or otherwiserefine a patient population suitable for treatment with an activatableantibody of the disclosure. For example, patients that test positive forboth the target and a protease that cleaves the substrate in thecleavable moiety (CM) of the activatable antibody being tested (e.g.,accumulate activated antibodies at the disease site) are identified assuitable candidates for treatment with such an activatable antibodycomprising such a CM. Likewise, patients that test negative for eitheror both of the target and the protease that cleaves the substrate in theCM in the activatable antibody being tested using these methods areidentified as suitable candidates for another form of therapy (i.e., notsuitable for treatment with the activatable antibody being tested). Insome embodiments, such patients that test negative with respect to afirst activatable antibody can be tested with other activatableantibodies comprising different CMs until a suitable activatableantibody for treatment is identified (e.g., an activatable antibodycomprising a CM that is cleaved by the patient at the site of disease).

In some embodiments in vivo imaging is used to identify or otherwiserefine a patient population suitable for treatment with an activatableantibody of the disclosure. For example, patients that test positive forboth the target and a protease that cleaves the substrate in thecleavable moiety (CM) of the activatable antibody being tested (e.g.,accumulate activated antibodies at the disease site) are identified assuitable candidates for treatment with such an activatable antibodycomprising such a CM. Likewise, patients that test negative areidentified as suitable candidates for another form of therapy (i.e., notsuitable for treatment with the activatable antibody being tested). Insome embodiments, such patients that test negative with respect to afirst activatable antibody can be tested with other activatableantibodies comprising different CMs until a suitable activatableantibody for treatment is identified (e.g., an activatable antibodycomprising a CM that is cleaved by the patient at the site of disease).

Pharmaceutical Compositions

The antibodies, conjugated antibodies, activatable antibodies and/orconjugated activatable antibodies of the disclosure (also referred toherein as “active compounds”), and derivatives, fragments, analogs andhomologs thereof, can be incorporated into pharmaceutical compositionssuitable for administration. Such compositions typically comprise theantibody, the conjugated antibody, activatable antibody and/orconjugated activatable antibody and a pharmaceutically acceptablecarrier. As used herein, the term “pharmaceutically acceptable carrier”is intended to include any and all solvents, dispersion media, coatings,antibacterial and antifungal agents, isotonic and absorption delayingagents, and the like, compatible with pharmaceutical administration.Suitable carriers are described in the most recent edition ofRemington's Pharmaceutical Sciences, a standard reference text in thefield, which is incorporated herein by reference. Suitable examples ofsuch carriers or diluents include, but are not limited to, water,saline, ringer's solutions, dextrose solution, and 5% human serumalbumin. Liposomes and non-aqueous vehicles such as fixed oils may alsobe used. The use of such media and agents for pharmaceutically activesubstances is well known in the art. Except insofar as any conventionalmedia or agent is incompatible with the active compound, use thereof inthe compositions is contemplated. Supplementary active compounds canalso be incorporated into the compositions.

A pharmaceutical composition of the disclosure is formulated to becompatible with its intended route of administration. Examples of routesof administration include parenteral, e.g., intravenous, intradermal,subcutaneous, oral (e.g., inhalation), transdermal (i.e., topical),transmucosal, and rectal administration. Solutions or suspensions usedfor parenteral, intradermal, or subcutaneous application can include thefollowing components: a sterile diluent such as water for injection,saline solution, fixed oils, polyethylene glycols, glycerine, propyleneglycol or other synthetic solvents; antibacterial agents such as benzylalcohol or methyl parabens; antioxidants such as ascorbic acid or sodiumbisulfite; chelating agents such as ethylenediaminetetraacetic acid(EDTA); buffers such as acetates, citrates or phosphates, and agents forthe adjustment of tonicity such as sodium chloride or dextrose. The pHcan be adjusted with acids or bases, such as hydrochloric acid or sodiumhydroxide. The parenteral preparation can be enclosed in ampoules,disposable syringes or multiple dose vials made of glass or plastic.

Pharmaceutical compositions suitable for injectable use include sterileaqueous solutions (where water soluble) or dispersions and sterilepowders for the extemporaneous preparation of sterile injectablesolutions or dispersion. For intravenous administration, suitablecarriers include physiological saline, bacteriostatic water, CremophorEL™ (BASF, Parsippany, N.J.) or phosphate buffered saline (PBS). In allcases, the composition must be sterile and should be fluid to the extentthat easy syringeability exists. It must be stable under the conditionsof manufacture and storage and must be preserved against thecontaminating action of microorganisms such as bacteria and fungi. Thecarrier can be a solvent or dispersion medium containing, for example,water, ethanol, polyol (for example, glycerol, propylene glycol, andliquid polyethylene glycol, and the like), and suitable mixturesthereof. The proper fluidity can be maintained, for example, by the useof a coating such as lecithin, by the maintenance of the requiredparticle size in the case of dispersion and by the use of surfactants.Prevention of the action of microorganisms can be achieved by variousantibacterial and antifungal agents, for example, parabens,chlorobutanol, phenol, ascorbic acid, thimerosal, and the like. In someembodiments, it will be desirable to include isotonic agents, forexample, sugars, polyalcohols such as manitol, sorbitol, sodium chloridein the composition. Prolonged absorption of the injectable compositionscan be brought about by including in the composition an agent thatdelays absorption, for example, aluminum monostearate and gelatin.

Sterile injectable solutions can be prepared by incorporating the activecompound in the required amount in an appropriate solvent with one or acombination of ingredients enumerated above, as required, followed byfiltered sterilization. Generally, dispersions are prepared byincorporating the active compound into a sterile vehicle that contains abasic dispersion medium and the required other ingredients from thoseenumerated above. In the case of sterile powders for the preparation ofsterile injectable solutions, methods of preparation are vacuum dryingand freeze-drying that yields a powder of the active ingredient plus anyadditional desired ingredient from a previously sterile-filteredsolution thereof.

Oral compositions generally include an inert diluent or an ediblecarrier. They can be enclosed in gelatin capsules or compressed intotablets. For the purpose of oral therapeutic administration, the activecompound can be incorporated with excipients and used in the form oftablets, troches, or capsules. Oral compositions can also be preparedusing a fluid carrier for use as a mouthwash, wherein the compound inthe fluid carrier is applied orally and swished and expectorated orswallowed. Pharmaceutically compatible binding agents, and/or adjuvantmaterials can be included as part of the composition. The tablets,pills, capsules, troches and the like can contain any of the followingingredients, or compounds of a similar nature: a binder such asmicrocrystalline cellulose, gum tragacanth or gelatin; an excipient suchas starch or lactose, a disintegrating agent such as alginic acid,Primogel, or corn starch; a lubricant such as magnesium stearate orSterotes; a glidant such as colloidal silicon dioxide; a sweeteningagent such as sucrose or saccharin; or a flavoring agent such aspeppermint, methyl salicylate, or orange flavoring.

For administration by inhalation, the compounds are delivered in theform of an aerosol spray from pressured container or dispenser thatcontains a suitable propellant, e.g., a gas such as carbon dioxide, or anebulizer.

Systemic administration can also be by transmucosal or transdermalmeans. For transmucosal or transdermal administration, penetrantsappropriate to the barrier to be permeated are used in the formulation.Such penetrants are generally known in the art, and include, forexample, for transmucosal administration, detergents, bile salts, andfusidic acid derivatives. Transmucosal administration can beaccomplished through the use of nasal sprays or suppositories. Fortransdermal administration, the active compounds are formulated intoointments, salves, gels, or creams as generally known in the art.

The compounds can also be prepared in the form of suppositories (e.g.,with conventional suppository bases such as cocoa butter and otherglycerides) or retention enemas for rectal delivery.

In one embodiment, the active compounds are prepared with carriers thatwill protect the compound against rapid elimination from the body, suchas a controlled release formulation, including implants andmicroencapsulated delivery systems. Biodegradable, biocompatiblepolymers can be used, such as ethylene vinyl acetate, polyanhydrides,polyglycolic acid, collagen, polyorthoesters, and polylactic acid.Methods for preparation of such formulations will be apparent to thoseskilled in the art. The materials can also be obtained commercially fromAlza Corporation and Nova Pharmaceuticals, Inc. Liposomal suspensions(including liposomes targeted to infected cells with monoclonalantibodies to viral antigens) can also be used as pharmaceuticallyacceptable carriers. These can be prepared according to methods known tothose skilled in the art, for example, as described in U.S. Pat. No.4,522,811.

It is especially advantageous to formulate oral or parenteralcompositions in dosage unit form for ease of administration anduniformity of dosage. Dosage unit form as used herein refers tophysically discrete units suited as unitary dosages for the subject tobe treated; each unit containing a predetermined quantity of activecompound calculated to produce the desired therapeutic effect inassociation with the required pharmaceutical carrier. The specificationfor the dosage unit forms of the disclosure are dictated by and directlydependent on the unique characteristics of the active compound and theparticular therapeutic effect to be achieved, and the limitationsinherent in the art of compounding such an active compound for thetreatment of individuals.

The pharmaceutical compositions can be included in a container, pack, ordispenser together with instructions for administration.

The invention will be further described in the following examples, whichdo not limit the scope of the invention described in the claims.

EXAMPLES Example 1 Selection of Human ScFvs of the Embodiments that BindHuman and/or Mouse PDL1

This Example demonstrates that ScFvs (single-chain variable fragments)of the embodiments that bind PDL1 can be selected from a phage displaylibrary of ScFvs with diverse CDR sequences, and that such binding caninhibit PDL1 binding to PD1 and B7-1.

ScFvs were selected from a fully human ScFv library displayed on M13bacteriophage; ScFv phage selection was conducted under contract withCreative Biolabs, Shirley, N.Y. A fusion protein comprised of theextracellular domain (ECD) of human PDL1 or mouse PDL1, with a carboxyterminal His6 tag (Sino Biological, Cat. No. 10084-H02H-200) was used asthe antigen in three alternating rounds of selection for ScFvs displayedon M13 bacteriophage that bind PDL1. In the first round, bound phagewere released by trypsin digestion, and in subsequent rounds, phage wereeluted by human PD1 fusion protein (R&D Systems; Cat. No. 1080-PD-050)competition. Five (5) unique ScFvs that bind PDL1 were isolated. Table 1lists the 5 ScFvs and SEQ ID NOs of their respective nucleic acidsequences and amino acid sequences.

TABLE 1 SEQ ID NOs of selected ScFvs ScFv Nucleic acid sequence Aminoacid sequence PDL1 c8 SEQ ID NO: 1 SEQ ID NO: 2 PDL1 c12 SEQ ID NO: 3SEQ ID NO: 4 PDL1 c16 SEQ ID NO: 5 SEQ ID NO: 6 PDL1 c20 SEQ ID NO: 7SEQ ID NO: 8 PDL1 c60 SEQ ID NO: 9 SEQ ID NO: 10

The nucleic acid and amino acid sequences of each of the anti-PDL1 ScFvs(with CDRs underlined) are shown below:

SEQ ID NO: 1 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAGATATTACTGCGTCGGGTTAGAGGACAACGTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAGATCGAAGATTGCTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGCGGTGGAGGCGGTTCAGGCGGAGGTGGCAGCGGCGGTGGCGGGTCGACGGACATCCAGATGACCCAGTCTCCATCCTCCCTGTCTGCATCTGTAGGAGACAGAGTCACCATCACTTGCCGGGCAAGTCAGAGCATTAGCAGCTATTTAAATTGGTATCAGCAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCTATAAGGCATCCCGTTTGCAAAGTGGGGTCCCATCAAGGTTCAGTGGCAGTGGATCTGGGACAGATTTCACTCTCACCATCAGCAGTCTGCAACCTGAAGATTTTGCAACTTACTACTGTCAACAGCGTGCGCTTAAGCCTGTGACGTTCGGCCAAGGGA CCAAGGTGGAAATCAAACGGSEQ ID NO: 2 EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSDITASGQRTTYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARSKIAFDYWGQGTLVTVSSGGGGSGGGGSGGGGSTDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYKASRLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQRALKPVTFGQGTKVEIKR SEQ ID NO: 3GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTATCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTAATAAGGATGGTCATTATACAAGTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAAAATCTTGATGAGTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGCGGTGGAGGCGGTTCAGGCGGAGGTGGCAGCGGCGGTGGCGGGTCGACGGACATCCAGATGACCCAGTCTCCATCCTCCCTGTCTGCATCTGTAGGAGACAGAGTCACCATCACTTGCCGGGCAAGTCAGAGCATTAGCAGCTATTTAAATTGGTATCAGCAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCTATGCTGCATCCAGTTTGCAAAGTGGGGTCCCATCAAGGTTCAGTGGCAGTGGATCTGGGACAGATTTCACTCTCACCATCAGCAGTCTGCAACCTGAAGATTTTGCAACTTACTACTGTCAACAGAGTTACAGTACCCCTAATACGTTCGGCCAAGGGA CCAAGGTGGAAATCAAACGGSEQ ID NO: 4 EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSINKDGHYTSYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKNLDEFDYWGQGTLVTVSSGGGGSGGGGSGGGGSTDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYSTPNTFGQGTKVEIKR SEQ ID NO: 5GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCATCTATTATGGCTACTGGTGCTGGTACATTGTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAAGATGGTGCGGGGTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGCGGTGGAGGCGGTTCAGGCGGAGGTGGCAGCGGCGGTGGCGGGTCGACGGACATCCAGATGACCCAGTCTCCATCCTCCCTGTCTGCATCTGTAGGAGACAGAGTCACCATCACTTGCCGGGCAAGTCAGAGCATTAGCAGCTATTTAAATTGGTATCAGCAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCTATTCTGCATCCCAGTTGCAAAGTGGGGTCCCATCAAGGTTCAGTGGCAGTGGATCTGGGACAGATTTCACTCTCACCATCAGCAGTCTGCAACCTGAAGATTTTGCAACTTACTACTGTCAACAGGCGAATTCGCGGCCTTCTACGTTCGGCCAAGGGA CCAAGGTGGAAATCAAACGGSEQ ID NO: 6 EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIMATGAGTLYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKDGAGFDYWGQGTLVTVSSGGGGSGGGGSGGGGSTDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYSASQLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQANSRPSTFGQGTKVEIKR SEQ ID NO: 7GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGTAGTGGGTCTCAACTATTACTTCTTCTGGTGCTGCTACATATTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAAAATTATACTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGCGGTGGAGGCGGTTCAGGCGGAGGTGGCAGCGGCGGTGGCGGGTCGACGGACATCCAGATGACCCAGTCTCCATCCTCCCTGTCTGCATCTGTAGGAGACAGAGTCACCATCACTTGCCGGGCAAGTCAGAGCATTAGCAGCTATTTAAATTGGTATCAGCAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCTATAATGCATCCTCCTTGCAAAGTGGGGTCCCATCAAGGTTCAGTGGCAGTGGATCTGGGACAGATTTCACTCTCACCATCAGCAGTCTGCAACCTGAAGATTTTGCAACTTACTACTGTCAACAGTATACTTATGGTCCTGGTACGTTCGGCCAAGGGA CCAAGGTGGAAATCAAACGGSEQ ID NO: 8 EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLQWVSTITSSGAATYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKNYTGFDYWGQGTLVTVSSGGGGSGGGGSGGGGSTDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYNASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYTYGPGTFGQGTKVEIKR SEQ ID NO: 9GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTATTCTACTGGTGGTGCTACAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGCGGTGGAGGCGGTTCAGGCGGAGGTGGCAGCGGCGGTGGCGGGTCGACGGACATCCAGATGACCCAGTCTCCATCCTCCCTGTCTGCATCTGTAGGAGACAGAGTCACCATCACTTGCCGGGCAAGTCAGAGCATTAGCAGCTATTTAAATTGGTATCAGCAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCTATTATGCATCCACTTTGCAAAGTGGGGTCCCATCAAGGTTCAGTGGCAGTGGATCTGGGACAGATTTCACTCTCACCATCAGCAGTCTGCAACCTGAAGATTTTGCAACTTACTACTGTCAACAGGATAATGGTTATCCTTCTACGTTCGGCCAAGGGA CCAAGGTGGAAATCAAACGGSEQ ID NO: 10 EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIYSTGGATAYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSAGFDYWGQGTLVTVSSGGGGSGGGGSGGGGSTDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYYASTLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGQGTKVEIKR

FIG. 1A shows by ELISA-based binding that PDL1 c60 ScFv-phage bindsspecifically to human and mouse PDL1. Briefly, human PDL1, mouse PDL1,human PD1, mouse PD1, human 41BBLig or Notch1 (R&D Systems) wereadsorbed to separate wells of a 96-well ELISA plate. Phage were appliedto the plate and allowed to bind. Bound phage were visualized with ananti-M13-HRP conjugate (GE Healthcare, Piscataway, N.Y.) and developedwith the chromogenic substrate tetramethyl benzidine (TMB) (ThermoScientific, Rockford, Ill.).

FIG. 2A shows that inclusion of PD1 can inhibit the binding of PDL1ScFv-phage binding to PDL1 in an ELISA binding assay. Briefly, humanPDL1 or mouse PDL1 (R&D Systems) was adsorbed to separate wells of a96-well ELISA plate. Phage were applied to the plate in the presence orabsence of human or mouse PD1-Fc (R&D Systems) and allowed to bind.Bound phage were visualized with an anti-M13-HRP conjugate (GEHealthcare, Piscataway, N.Y.) and developed with the chromogenicsubstrate tetramethyl benzidine (TMB) (Thermo Scientific, Rockford,Ill.). Phage binding was reduced in the presence of PD1-Fc,demonstrating that the binding epitope of the phage overlaps with thatof PD1 binding.

Example 2 Production and Testing of Fully Human Anti-PDL1 c60 IgGAntibodies

This Example demonstrates that PDL1 c60 ScFv-phage that bind human andmouse PDL1 can be converted into fully human IgG antibodies that retainhuman and mouse PDL1 binding.

Production of fully human IgGs comprising the variable domains of PDL1c60 was accomplished using techniques similar to those described in PCTPublication No. WO 2010/081173. DNA molecules encoding the variabledomains of PDL1 c60 ScFv-phage were cloned into expression vectors forthe expression of fully human IgGs. Light chain (Lc) variable domainswere amplified from the ScFv templates. Vector (LcpOP (modified frompCDNA3, Invitrogen, Carlsbad, Calif.)) and amplified DNA were cut withBsiWI and EcoRI overnight, combined by ligation and transformed into E.coli MC1061 cells. Heavy chain (Hc) variable domains were amplified fromScFv templates. Fully human IgGs anti-PDL1 c60 were expressed fromtransiently transfected HEK-293 cells and purified from the culturesupernatant by Protein A chromatography.

FIG. 3A shows that the fully human anti-PDL1 c60 IgG binds human andmouse PDL1, with affinity for human PDL1 of 1 nM and for mouse PDL1 of30 nM. Briefly human PDL1-Fc or mouse PDL1-Fc (R & D Systems,Minneapolis, Minn.) was adsorbed to the wells of a 96-well ELISA plate.Purified anti-PDL1 c60 was applied to the plate and allowed to bind.Bound antibody was visualized with an anti-human IgG-HRP conjugate, Fabspecific, (Sigma, St Louis, Mo.: Cat #A0293-1ML) and developed with thechromogenic substrate TMB.

Example 3 Affinity Maturation of Anti-PDL1 Antibodies of the Embodiments

This Example demonstrates the isolation of antibodies of the embodimentswith improved binding kinetics and manufacturability profile.

Anti-PDL1 antibodies were isolated from libraries with CDRs modifiedfrom anti-PDL1 c60. Such libraries were designed as shown in Tables 2and 3. Four libraries of Fab-Phage, based on the sequence of anti-PDL1c60, were constructed using degenerate synthetic DNA. Residues wereeither varied by randomization at each indicated nucleotide. Inaddition, within libraries 3 and 6, additional randomized residues wereadded to CDR3 of the heavy chain. Libraries were transfected into E.coli strain TG1 and phage were prepared following super-infection withM13KO7 (Invitrogen).

Three rounds of selection were performed for each library withincreasing stringency. Three alternating rounds of selection were doneby mixing biotinylated Human PDL1 or Biotinylated mouse PDL1 with phagethat were blocked with 100 μg/mL pooled human IgG (huIgG, or hIgG) and2% non-fat dried milk (NFDM) in Tris-buffered saline (TBS; 40 mM Tris,129 mM NaCl, pH 7.4). Following incubation at room temperature Bio-PDL1bound to phage were captured with streptavidin magnetic beads which werewashed extensively at 37° C. and the remaining bound phage eluted with100 mM triethanolamine (TEA) (Sigma, St. Louis, Mo.) and expandedthrough E. coli TG1. Selected Lc libraries were combined with Helibraries and each subjected to an additional seven rounds of selection.

TABLE 2 CDR sequences for affinity maturation variable heavy chainlibraries IMGT . . . 32 33 34 39 40 . . . 55 56 57 58 59 60 61 62 63 6667 . . . 107 108 109 110 111 112 113 VH3-29 germline S Y A M S A I S G SG G S T Y Y — — — — — — — (SEQ ID NO: 158) (SEQ ID NO: 159) Clone 60 S YA M S S I Y S T G G A T A Y S S A G F D Y (SEQ ID NO: 158) (SEQ ID NO:160) (SEQ ID NO: 162) H2 x x x x x x x 3.36E+07 (SEQ ID NO: 161) H3 walk(SEQ ID NO: 163) x x 1.02E+04 (SEQ ID NO: 164) x x (SEQ ID NO: 165) x x(SEQ ID NO: 166) x x (SEQ ID NO: 167) x x (SEQ ID NO: 168) x x (SEQ IDNO: 169) x x (SEQ ID NO: 170) x x (SEQ ID NO: 171) x x (SEQ ID NO: 172)x x H3 insertions: 4xNNK between G110 and F111 (SEQ ID NO: 173) T(x)₁₋₃F1E+06

TABLE 3 CDR sequences for affinity maturation variable light chainlibraries IMGT . . . 27 28 29 30 31 32 . . . 56 57 58 66 . . . 104 105106 107 108 109 110 111 112 Vk1-39 germline Q S I S S Y A A S S C Q Q SY S T P P (SEQ ID NO: 174) (SEQ ID NO: 175) (SEQ ID NO: 177) Clone 60 QS I S S Y Y A S T C Q Q D N G Y P S T (SEQ ID NO: 174) (SEQ ID NO: 176)(SEQ ID NO: 178) L2nnk + L3 walk (SEQ ID NO: 179) x x x x 1.26E+07 (SEQID NO: 180) x x x x (SEQ ID NO: 181) x x x x (SEQ ID NO: 182) x x x x(SEQ ID NO: 183) x x x x (SEQ ID NO: 184) x x x x (SEQ ID NO: 185) x x xx (SEQ ID NO: 186) x x x x (SEQ ID NO: 187) x x x x (SEQ ID NO: 188) x xx x (SEQ ID NO: 189) x x x x (SEQ ID NO: 190) x x x x

Forty seven (47) individual isolates were chosen from the final pool.Phage were derived from each isolate and assayed for binding to humanPDL1-Fc, human B7-1-Fc and human CD28-Fc antigens (R&D Systems).Briefly, the antigens were adsorbed to the wells of a 96-well ELISAplate, each ligand on a separate plate. Phage were applied tocorrelative wells on each plate and allowed to bind. Bound phage werevisualized with an anti-M13-HRP conjugate and developed with thechromogenic substrate TMB. Based on the results of the ELISA and DNAsequence, 6 unique clones with matured heavy variable CDR3 domains and10 heavy variable CDR2 domains were chosen for further study. Thirteenphage clones, 10 CDR2 and 3 CDR3 were analyzed for their ability to bindmouse and human PDL1, and the results of a phage ELISA are shown in FIG.4A and FIG. 4B. All phage clones bind human PDL1 but not B7-1, inaddition, CDR2 clones C05 and G12 show strong binding to mouse PDL1 andCDR3 clone H9 showed weak binding to mouse PDL1. Table 4 lists the heavyvariable domains encoded by the clones and SEQ ID NOs for the nucleicacid sequences and amino acid sequences of their respective heavychains. The light variable domains for each are identical to that of c60(SEQ ID NO 11 and 12).

SEQ ID NO: 11 GACATCCAGATGACCCAGTCTCCATCCTCCCTGTCTGCATCTGTAGGAGACAGAGTCACCATCACTTGCCGGGCAAGTCAGAGCATTAGCAGCTATTTAAATTGGTATCAGCAGAAACCAGGGAAAGCCCCTAAGCTCCTGATCTATTATGCATCCACTTTGCAAAGTGGGGTCCCATCAAGGTTCAGTGGCAGTGGATCTGGGACAGATTTCACTCTCACCATCAGCAGTCTGCAACCTGAAGATTTTGCAACTTACTACTGTCAACAGGATAATGGTTATCCTTCTACGTTCGGCCAAGGGACCAAGGTGGAAATCAAACGG SEQ ID NO: 12DIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYYASTLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGQ GTKVEIKR

TABLE 4 Matured anti-PDL1 variable domains VH Nucleic acid sequenceAmino acid sequence PDL1 c1 SEQ ID NO: 13 SEQ ID NO: 14 PDL1 d1 SEQ IDNO: 15 SEQ ID NO: 16 PDL1 g7 SEQ ID NO: 17 SEQ ID NO: 18 PDL1 h9 SEQ IDNO: 19 SEQ ID NO: 20 PDL1 b10 SEQ ID NO: 21 SEQ ID NO: 22 PDL1 E10 SEQID NO: 23 SEQ ID NO: 24 PDL1 A05 SEQ ID NO: 25 SEQ ID NO: 26 PDL1 C05SEQ ID NO: 27 SEQ ID NO: 28 PDL1 C10 SEQ ID NO: 29 SEQ ID NO: 30 PDL1D08 SEQ ID NO: 31 SEQ ID NO: 32 PDL1 G09 SEQ ID NO: 33 SEQ ID NO: 34PDL1 G10 SEQ ID NO: 35 SEQ ID NO: 36 PDL1 G12 SEQ ID NO: 37 SEQ ID NO:38 PDL1 E11 SEQ ID NO: 39 SEQ ID NO: 40 PDL1 D01 SEQ ID NO: 41 SEQ IDNO: 42 PDL1 H06 SEQ ID NO: 43 SEQ ID NO: 44

SEQ ID NO: 13 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTATTCTACTGGTGGTGCTACAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTAGTCGGCCGGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCAC CGTCTCGAGCSEQ ID NO: 14 EVQLLESGGGLVQPGGSLRTSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIYSTGGATAYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSS AGQSRPGFDYWGQGTLVTVSSSEQ ID NO: 15 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTATTCTACTGGTGGTGCTACAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTCGTGGCCGGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCAC CGTCTCGAGCSEQ ID NO: 16 EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIYSTGGATAYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSS AGQSWPGFDYWGQGTLVTVSSSEQ ID NO: 17 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTATTCTACTGGTGGTGCTACAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTCAGTCGTTTCCGGGTTTTGACTACTGGGGCCAGGGAACCCTGGT CACCGTCTCGAGCSEQ ID NO: 18 EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIYSTGGATAYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSS AGQSFPGFDYWGQGTLVTVSSSEQ ID NO: 19 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTATTCTACTGGTGGTGCTACAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATGGTCTGCTGCTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGC SEQ ID NO: 20EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIYSTGGATAYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWS AAFDYWGQGTLVTVSSSEQ ID NO: 21 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTATTCTACTGGTGGTGCTACAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATGGTCTGCTGCTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGC SEQ ID NO: 22EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIYSTGGATAYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWS AGYDYWGQGTLVTVSSSEQ ID NO: 23 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTATTCTACTGGTGGTGCTACAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATGGTCTAAGGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGC SEQ ID NO: 24EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIYSTGGATAYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWS KGFDYWGQGTLVTVSSSEQ ID NO: 25 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTGGAAGTAGGGTATTGTGACAGTGAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGA GC SEQ ID NO: 26EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWKQGIVTVYDSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSA GFDYWGQGTLVTVSEQ ID NO: 27 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTGGCGGAATGGTATTGTTACAGTTAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGA GC SEQ ID NO: 28EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRNGIVTVYDSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSA GFDYWGQGTLVTVSSSEQ ID NO: 29 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAGATATTTGGAAGTAGGGTATGGTTACAGTGAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGA GC SEQ ID NO: 30EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSDIWKQGMVTVYDSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSA GFDYWGQGTLVTVSSSEQ ID NO: 31 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCATCGATTTGGAGGTAGGGTCTGGCGACAGCGAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGA GC SEQ ID NO: 32EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRQGLATAYDSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSA GFDYWGQGTLVTVSSSEQ ID NO: 33 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAGAGATTGTGGCTACTGGTATTTTGACAAGTAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGA GC SEQ ID NO: 34EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSEIVATGILTSYDSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSA GFDYWGQGTLVTVSSSEQ ID NO: 35 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCATCGATTGGTCGGTAGGGTTTGATTACAGTTAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGA GC SEQ ID NO: 36EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIGRQGLITVYDSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSA GFDYWGQGTLVTVSSSEQ ID NO: 37 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCATCTATTTGGTATTAGGGTCTGGTGACAGTTAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGA GC SEQ ID NO: 38EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWYQGLVTVYDSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSA GFDYWGQGTLVTVSSSEQ ID NO: 39 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAGATATTTGGAAGTAGGGTTTTGCTACAGCGAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGA GC SEQ ID NO: 40EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSDIWKQGFATADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSAG FDYWGQGTLVTVSSSEQ ID NO: 41 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTGGAAGTAGGGTATTGTGACAGTGAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGA GC SEQ ID NO: 42EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWKQGIVTVYDSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSA GFDYWGQGTLVTVSSSEQ ID NO: 43 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCATCGATTTGGAGGTAGGGTCTGGCGACAGCGAGCTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATCTTCTGCTGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGA GC SEQ ID NO: 44EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRQGLATAYDSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKSSA GFDYWGQGTLVTVSS

Example 4 Isolation and Testing of Affinity Matured Anti-PDL1 Antibodiesof the Embodiments

This Example demonstrates that matured PDL1 Fab-phage that bind humanand mouse PDL1 can be converted into fully human IgG antibodies thatretain human and show enhanced mouse PDL1 binding.

Production of fully human IgGs comprising the variable domains of thematured clones was accomplished using techniques similar to thosedescribed in PCT Publication No. WO 2010/081173. DNA encoding thevariable domains of anti-PDL1 Fab-Phage clones C1, D1, G7, C05, G12 andcombinations of heavy variable CDR3 domains of anti-PDL1 Fab-Phageclones C05 or G12 with anti-PDL1 Fab-Phage clones heavy variable CDR2domains of B10, E10 or H9 were cloned into expression vectors for theexpression of fully human IgGs. The light variable domains for each areidentical to that of c60 (SEQ ID NO: 10). Light chain (Lc) variabledomains were amplified from the Fab templates. Vector (LcpOP (modifiedfrom pCDNA3, Invitrogen, Carlsbad, Calif.)) and amplified DNA were cutwith BsiWI and EcoRI overnight, combined by ligation and transformedinto E. coli MC1061 cells. Heavy chain (Hc) variable domains wereamplified from Fab templates. Fully human IgGs anti-PDL1 antibodies wereexpressed from transiently transfected HEK-293 cells and purified fromthe culture supernatant by Protein A chromatography.

The affinity matured anti-PDL1 antibodies were analyzed for theirability to bind human and mouse PDL1. Briefly human PDL1-Fc or mousePDL1-Fc (R & D Systems, Minneapolis, Minn.) was adsorbed to the wells ofa 96-well ELISA plate. Purified anti-PDL1 antibodies were applied to theplate and allowed to bind. Bound antibody was visualized with ananti-human IgG-HRP conjugate, Fab specific, (Sigma, St Louis, Mo., Cat#A0293-1ML) and developed with the chromogenic substrate TMB. FIGS. 5Aand B show that combining the matured heavy variable CDR3 domains withthe heavy variable CDR2 domains results in antibodies with enhancedaffinity towards human PDL1. In addition, the combination of the maturedheavy variable CDR2 domain C05 with the heavy variable CD3 domain H9results in an antibody with high affinity for both human and mouse PDL1.Table 5 provides the SEQ ID NOs for the nucleic acid sequences and aminoacids sequences of the respective variable heavy chains.

The anti-PDL1 antibodies C5H9, C5B10 and C5E10 were furthercharacterized for their species specificity towards binding to PDL1 andother closely related proteins. Briefly human PDL1-Fc, mouse PDL1-Fc (R& D Systems, Minneapolis, Minn.) or cynomolgus monkey (cyno) PDL1-Fc(Sino biological) were adsorbed to the wells of a 96-well ELISA plate.Purified anti-PDL1 antibodies were applied to the plate and allowed tobind. Bound antibody was visualized with an anti-human IgG-HRPconjugate, Fab specific, (Sigma, St Louis, Mo.; Cat #A0293-1ML) anddeveloped with the chromogenic substrate TMB. FIGS. 6A and 6B show thatC5H9 binds to human and mouse PDL1 with near equal affinity and C5B10and C5E10 only bind human PDL1. None of the antibodies tested bind toeither human B7-1 (FIG. 6D) or human CD28 (FIG. 6C), two closely relatedproteins. FIG. 7A shows that anti-PDL1 antibody C5H9 binds with high andequal affinity to human, mouse and cyno PDL1, but not to human B7H3(also referred to as B7-H3) (R&D Systems, Minneapolis, Minn.).

TABLE 5 Variable heavy domains of PDL1 antibodies of the embodiments VHNucleic acid sequence Amino acid sequence PDL1 C5H9 SEQ ID NO: 45 SEQ IDNO: 46 PDL1 C5B10 SEQ ID NO: 47 SEQ ID NO: 48 PDL1 C5E10 SEQ ID NO: 49SEQ ID NO: 50 PDL1 G12H9 SEQ ID NO: 51 SEQ ID NO: 52 PDL1 G12B10 SEQ IDNO: 53 SEQ ID NO: 54 PDL1 G12E10 SEQ ID NO: 55 SEQ ID NO: 56

SEQ ID NO: 45 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGCAAGGGGCTGGAGTGGTTCTCAAGTATTTGGCGGAATGGTATTGTTACAGTTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATGGTCTGCTGCTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGC SEQ ID NO: 46EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRNGIVTVYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWS AAFDYWGQGTLVTVSSSEQ ID NO: 47 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTGGCGGAATGGTATTGTTACAGTTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATGGTCTGCTGGTTATGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGC SEQ ID NO: 48EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRNGIVTVYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWS AGYDYWGQGTLVTVSSSEQ ID NO: 49 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTGGCGGAATGGTATTGTTACAGTTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATGGTCTAAGGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGC SEQ ID NO: 50EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRNGIVTVYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWS KGFDYWGQGTLVTVSSSEQ ID NO: 51 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCATCTATTTGGTATCAGGGTCTGGTGACAGTTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATGGTCTGCTGCTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGC SEQ ID NO: 52EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMetSWVRQAPGKGLEWVSSIWYQGLVTVYADSVKGRFTISRDNSKNTLYLQMetNSLRAEDTAVYYC AKWSAAFDYWGQGTLVTVSSSEQ ID NO: 53 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTGGCGGAATGGTATTGTTACAGTTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATGGTCTGCTGGTTATGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGC SEQ ID NO: 54EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWYQGLVTVYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWS AGYDYWGQGTLVTVSSSEQ ID NO: 55 GAGGTGCAGCTGTTGGAGTCTGGGGGAGGCTTGGTACAGCCTGGGGGGTCCCTGAGACTCTCCTGTGCAGCCTCTGGATTCACCTTTAGCAGCTATGCCATGAGCTGGGTCCGCCAGGCTCCAGGGAAGGGGCTGGAGTGGGTCTCAAGTATTTGGCGGAATGGTATTGTTACAGTTTACGCAGACTCCGTGAAGGGCCGGTTCACCATCTCCAGAGACAATTCCAAGAACACGCTGTATCTGCAAATGAACAGCCTGAGAGCCGAGGACACGGCCGTATATTACTGTGCGAAATGGTCTAAGGGTTTTGACTACTGGGGCCAGGGAACCCTGGTCACCGTCTCGAGC SEQ ID NO: 56EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWYQGLVTVYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWS KGFDYWGQGTLVTVSS

Example 5 Germline Revisions in Anti-PDL1 Antibody C5H9 Light VariableDomain Enhances Manufacturability and Reduces Potential Immunogenicity

This example describes an additional anti-PDL1 antibody embodiment thatexhibits reduced predicted immunogenicity, reduced aggregation, andimproved expression.

In silico immunogenicity prediction, using ProPred revealed a strongpotential epitope in CDR2 of the light variable domain of C5H9;anti-PDL1 antibody C5H9, also referred to herein as C5H9, comprises alight chain comprising SEQ ID NO: 12 and a heavy chain comprising SEQ IDNO: 46. Alignment of the light variable domain of C5H9 with humangermline antibodies revealed two amino acids in CDR2 that when revertedto germline eliminated the predicted epitope. The residues areunderlined and in bold text in the sequence shown below in SEQ ID NO:12.

Furthermore, framework 4 of the C5H9 light chain was modified asindicated with bold italics in SEQ ID NO: 58 substituting glycine (G)for glutamine (Q) in the J region. This modification was aimed atincreasing the flexibility of the junction between variable and constantregions, potentially reducing the tendency of C5H9 to form aggregates.The resultant DNA and amino acid sequences are described by SEQ ID NO:57 and SEQ ID NO: 58, respectively. The resultant anti-PDL1 antibody,referred to herein as anti-PDL1 antibody C5H9v2, also referred to hereinas C5H9v2, comprises a light chain comprising SEQ ID NO: 58 and a heavychain comprising SEQ ID NO: 46.

SEQ ID NO: 12 DIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIY Y AS TLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGQ GTKVEIKR SEQ ID NO: 57GATATTCAGATGACCCAGAGCCCGAGCAGCCTGAGCGCGAGCGTGGGCGATCGCGTGACCATTACCTGCCGCGCGAGCCAGAGCATTAGCAGCTATCTGAACTGGTATCAGCAGAAACCGGGCAAAGCGCCGAAACTGCTGATTTATGCGGCGAGCAGCCTGCAGAGCGGCGTGCCGAGCCGCTTTAGCGGCAGCGGCAGCGGCACCGATTTTACCCTGACCATTAGCAGCCTGCAGCCGGAAGATTTTGCGACCTATTATTGCCAGCAGGATAACGGCTATCCGAGCACCTTTGGCGGCGGCACCAAAGTGGAAATTAAACGC SEQ ID NO: 58DIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFG

GTKVEIKR

FIGS. 8A and 8B show that germline revisions described in SEQ ID NO: 58reduces the predicted immunogenicity (top panel) and aggregationpotential, and increases the expression level by three fold.

Example 6 In Vitro Characterization of Anti-PDL1 Antibodies C5H9 andC5H9v2

This Example demonstrates the binding specificities and biologicalactivities of anti-PDL1 antibodies of the disclosure.

Production of fully human IgGs comprising the variable domains of thematured clones was accomplished using techniques similar to thosedescribed in PCT Publication No. WO 2010/081173. DNA encoding the heavyvariable domains of anti-PDL1 antibody C5H9 (nucleic acid SEQ ID NO: 45,amino acid SEQ ID NO: 46) were amplified and cloned into vectors for theexpression of fully human IgGs. DNA encoding the light variable domainsof anti-PDL1 antibody C5H9 (nucleic acid SEQ ID NO: 11; amino acid SEQID NO: 12) were amplified and cloned into vectors for the expression offully human IgGs. Similarly, DNA encoding the heavy variable domains ofanti-PDL1 antibody C5H9 (nucleic acid SEQ ID NO: 45; amino acid SEQ IDNO: 46) were amplified and cloned into vectors for the expression ofchimeric mouse IgG2as. DNA encoding the light variable domains ofanti-PDL1 antibody C5H9v2 (nucleic acid SEQ ID NO: 57, amino acid SEQ IDNO: 58) were amplified and cloned into vectors for the expression ofchimeric mouse IgG2as. Fully human IgGs or chimeric mouse IgG2aanti-PDL1 antibodies were expressed from transiently transfected HEK-293cells and purified from the culture supernatant by Protein Achromatography. Anti-PDL1 IgG antibody C5H9 comprises a heavy chaincomprising a heavy variable domain comprising SEQ ID NO: 46 and a lightchain comprising a light variable domain comprising SEQ ID NO: 12.Anti-PDL1 IgG antibody C5H9v2 comprises a heavy chain comprising a heavyvariable domain comprising SEQ ID NO: 46 and a light chain comprising alight variable domain comprising SEQ ID NO: 58.

Anti-PDL1 antibody C5H9v2 was characterized for species specific bindingto PDL1 and whether that antibody would bind a panel of human proteins.Briefly human PDL1-Fc, mouse PDL1-Fc (R & D Systems, Minneapolis, Minn.)or cynomolgus monkey (cyno) PDL1-Fc (Sino biological) was adsorbed tothe wells of a 96-well ELISA plate. Purified anti-PDL1 antibodies C5H9and C5H9v2 were applied to the plate and allowed to bind. Bound antibodywas visualized with an anti-human IgG-HRP conjugate, Fab specific,(Sigma, St Louis, Mo.; Cat #A0293-1ML) and developed with thechromogenic substrate TMB. FIGS. 9A to C show that both anti-PDL1antibodies C5H9 and C5H9v2 bind human, mouse and cyno PDL1 with nearequal affinity. EC₅₀ values for anti-PDL1 antibody C5H9v2 to human,cyno, rat and mouse PDL1 were also similar: 0.25 nM, 0.28 nM, 0.31 nM,and 0.30 nM, respectively.

In a similar experiment the binding of anti-PDL1 antibody C5H9 wasevaluated for binding to a panel of human and mouse proteins. Briefly,each protein, listed in FIG. 10A, was absorbed to the wells of an ELISAplate. Purified anti-PDL1 antibodies C5H9 and C5H9v2 were applied to theplate and allowed to bind. Bound antibody was visualized with ananti-human IgG-HRP conjugate, Fab specific, (Sigma, St Louis, Mo.; Cat#A0293-1ML) and developed with the chromogenic substrate TMB. Anti-PDL1antibody C5H9v2 binds only to human and mouse PDL1 demonstratingspecificity toward PDL1.

The biological activity of PDL1 is mediated through binding to PD1and/or to B7-1. Blockade of binding is a desired characteristic for atherapeutic antibody; therefore, the potency of blocking the interactionof PDL1 with PD1 and B7-1 was measured. Briefly, human, mouse or cynoPDL1 was adsorbed to the well of an ELISA plate. Biotinylated human,mouse or cyno PD1 or B7-1 was applied to the wells in the absence or thepresence of an increasing concentration of either anti-PDL1 antibodyC5H9 or anti-PDL1 antibody C5H9v2 and allowed to bind. Boundbiotinylated PD1 or B7-1 was visualized with a Streptavidin-HRPconjugate (Thermo Scientific, Cat. No. 21126) and developed with thechromogenic substrate TMB. FIG. 11A shows that both anti-PDL1 antibodyC5H9 and anti-PDL1 antibody C5H9v2 are potent blockers of either B7-1 orPD1 binding to PDL1, and that blockade includes all three species human,cyno and mouse with single digit nM EC₅₀'s.

Example 7 An Anti-PDL1 Antibody of the Disclosure Accelerates Inductionof Diabetes in NOD Mice

In this Example, anti-PDL1 antibody C5H9 was analyzed for the ability toinduce diabetes in NOD mice.

The NOD mice, substrain NOD/ShiLtJ, were obtained from JacksonLaboratory at 6 weeks and acclimated on site for 1 week. At 7 weeks,mice were checked for diabetes prior to enrollment, grouped, and dosedas set forth in Table 6.

TABLE 6 Groups and Doses for NOD study Dose (mg/kg) Dose Loading/ volumeGroup Count Treatment regular (mL/kg) Schedule Route 1 6 Control 20/1010 d2d×6 IP 2 6 Anti-PDL1 20/10 10 q2d×6 IP (C5H9) 3 6 Anti-PDL1 20/1010 d2d×6 IP (10F9G2)

FIG. 12A, which plots % non-diabetic versus number of days post initialdose, shows that anti-PDL1 antibody C5H9 antibody (Gr2-C5H9) inducesdiabetes in NOD mice similar to positive control anti-PDL1 antibody10F9G2 antibody. A control rat IgG2b did not induce diabetes in NODmice.

Anti-PDL1 antibody C5H9v2 was also tested for the ability to inducediabetes in NOD mice in a dose dependent matter, using a method similarto that described above, with 9-week old animals using the groups anddoses set forth in Table 7.

TABLE 7 Groups and doses for dose dependent NOD study Dose Dose volumeGroup Count Gender Treatment (mg/kg) (mL/kg) Schedule Route 1 8 F mIgG2a(C1.18.4) 25 10 Single dose IP 2 8 F Anti-PDL1 (C5H9v2) 25 10 Singledose IP 3 8 F Anti-PDL1 (C5H9v2) 5 10 Single dose IP 4 8 F Anti-PDL1(C5H9v2) 1 10 Single dose IP 5 8 F Anti-PDL1 (C5H9v2) 0.2 10 Single doseIP

FIG. 13A, which plots % non-diabetic versus number of days post initialdose, demonstrates that anti-PDL1 antibody C5H9v2 induces diabetes inNOD mice in a dose dependent matter.

Example 8 An Anti-PDL1 Antibody of the Embodiments Reduces MC38 Tumorsin Mice

In this Example, anti-PDL1 antibody C5H9v2 was analyzed for the abilityto reduce the growth of MC38 syngeneic tumors.

The mouse colon carcinoma cell line MC38 was obtained from ATCC(American Type Culture Collection, Manassas, Va.). MC38 cells were grownin RPMI-1640 supplemented with 10% fetal bovine serum at 37° C. in anatmosphere of 5% CO₂ in air. Cells were harvested during the logarithmicgrowth period, resuspended in PBS, and kept on ice for tumor induction.

Each mouse was inoculated subcutaneously at the right flank with 1×10⁶of MC38 cells in PBS for tumor development. The treatments were startedwhen the mean tumor size reached approximately 100-200 mm³ (no more than200 mm³). Tumor sizes were measured twice weekly in two dimensions usinga caliper, and the volume was expressed in mm³ using the formula: V=0.5a×b² where a and b are the long and short diameters of the tumor,respectively.

The mice were grouped and dosed as set forth in Table 8.

TABLE 8 Groups and doses for MC38 syngeneic study Dose Dose (mg/ volumeGroup Count Treatment kg) (mL/kg) Schedule Route 1 10 Anti-PDL1 10 10t.i.w. for 2 IP (10F9G2) weeks (MWF) 2 10 Anti-PDL1 10 10 t.i.w. for 2IP (C5H9v2) weeks (MWF) 3 10 mIgG2a + 10 10 t.i.w. for 2 IP Hamsterweeks (MWF) IgG1

FIG. 14A, which plots tumor volume versus number of days post initialdose, demonstrates that anti-PDL1 antibody C5H9v2 inhibits the growth ofMC38 syngeneic tumors similar to positive control anti-PDL1 antibody10F9G2.

Example 9 Anti-PDL1 Activatable Antibody C5H9v2 Masking Moieties

This Example describes identification of masking moieties (MM) to reducebinding of activatable antibodies of anti-PDL1 antibody C5H9v2 to theirtarget.

Anti-PDL1 antibody C5H9v2 and Fab were used to screen the librariesusing a method similar to that described in PCT InternationalPublication Number WO 2010/081173, published 15 Jul. 2010. The screeningconsisted of one round of MACS and three rounds of FACS sorting. Theinitial MACS was done with protein-A Dynabeads (Invitrogen) and theanti-PDL1 antibody C5H9v2 at a concentration of 100 nM. For MACS,approximately 1×10¹¹ cells were screened for binding and 6×10⁶ cellswere collected. Anti-PDL1 antibody C5H9v2, directly labeled withAlexafluor-488, was used as a probe for all FACS selections. In thefirst round of FACS, the cells were labeled with 100 nMAlexaFluor-anti-PDL1 antibody C5H9v2. In the second round of FACS, thecells were labeled with 10 nM AlexaFluor-anti-PDL1 antibody C5H9v2. Inthe third round of FACS, the cells were labeled with 1 nMAlexaFluor-anti-PDL1 antibody C5H9v2. The positive population from thethird FACS round was verified to be inhibited by recombinant human PDL1protein from binding to the anti-PDL1 antibody C5H9v2 and Fab.Individual peptide clones were identified by sequence analysis andsubsequently verified for their ability to bind the anti-PDL1 antibodyC5H9v2 and Fab.

The sequences of the anti-PDL1 antibody C5H9v2 masking moieties arelisted in Table 9.

TABLE 9 anti-PDL1 antibody C5H9v2 masking moieties (MM) MMAmino Acid Sequence SEQ ID NO PL01 YCEVSELFVLPWCMG SEQ ID NO: 208 PL02SCLMHPHYAHDYCYV SEQ ID NO: 426 PL03 LCEVLMLLQHPWCMG SEQ ID NO: 59 PL04IACRHFMEQLPFCHH SEQ ID NO: 60 PL05 FGPRCGEASTCVPYE SEQ ID NO: 61 PL06ILYCDSWGAGCLTRP SEQ ID NO: 62 PL07 GIALCPSHFCQLPQT SEQ ID NO: 63 PL08DGPRCFVSGECSPIG SEQ ID NO: 64 PL09 LCYKLDYDDRSYCHI SEQ ID NO: 65 PL10PCHPHPYBARPYCNV SEQ ID NO: 66 PL11 PCYWHPFFAYRYCNT SEQ ID NO: 67 PL12VCYYMBWLGRNWCSS SEQ ID NO: 68 PL13 LCDLFKLREFPYCMG SEQ ID NO: 69 PL14YLPCHFVPIGACNNK SEQ ID NO: 70 PL15 IFCHMGVVVPQCANY SEQ ID NO: 71 PL16ACHPHPYBARPYCNV SEQ ID NO: 72 PL17 PCHPAPYBARPYCNV SEQ ID NO: 73 PL18PCHPHAYDARPYCNV SEQ ID NO: 74 PL19 PCHPHPADARPYCNV SEQ ID NO: 75 PL20PCHPHPYAARPYCNV SEQ ID NO: 76 PL21 PCHPHPYDAAPYCNV SEQ ID NO: 77 PL22PCHPHPYDARPACNV SEQ ID NO: 78 PL23 PCHPHPYDARPYCAV SEQ ID NO: 79 PL24PCHAHPYBARPYCNV SEQ ID NO: 80 PL25 PCHPHPYDARAYCNV SEQ ID NO: 81

Example 10 Activatable Antibodies Comprising Anti-PDL1 Antibody C5H9v2

This Example describes examples of activatable antibodies of thedisclosure comprising anti-PDL1 antibody C5H9v2.

Anti-PDL1 activatable antibodies comprising an anti-PDL1 antibody C5H9v2masking moiety, a cleavable moiety, and anti-PDL1 antibody C5H9v2 wereproduced according to methods similar to those described in PCTPublication Nos. WO 2009/025846 and WO 2010/081173. Quality control ofthe resultant activatable antibodies indicated that most comprised atleast 95% monomer. The amino acid and nucleic acid sequences of severalactivatable antibodies comprising anti-PDL1 antibody C5H9v2 are providedbelow. Each activatable antibody comprises anti-PDL1 antibody C5H9v2having the variable heavy chain amino acid sequence shown in SEQ ID NO:46 and a light chain amino acid sequence selected from the groupconsisting of the amino acid sequences shown in SEQ ID NO: 83, 85, 87,89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117,119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145,147, 149, 151, 153, 155, 157, 931, 933, 935, 937, 939, 941, 943, 945,947, 949, 951, 953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973,975, 977, 979, 981, 983, 985, 987, 989, 991, 993, 995, 997, 999, 1001,1003, 1005, 1144-1191, 1200, and 1201 below.

While the sequences shown below include the spacer sequence of SEQ IDNO: 923, those of ordinary skill in the art appreciate that theactivatable anti-PDL1 antibodies of the disclosure can include anysuitable spacer sequence, such as, for example, a spacer sequenceselected from the group consisting of QGQSGS (SEQ ID NO: 923); GQSGS(SEQ ID NO: 1192); QSGS (SEQ ID NO: 1193); SGS (SEQ ID NO: 1194); GS(SEQ ID NO: 1195); S; QGQSGQG (SEQ ID NO: 924); GQSGQG (SEQ ID NO: 395);QSGQG (SEQ ID NO: 925); SGQG (SEQ ID NO: 926); GQG (SEQ ID NO: 927); QG(SEQ ID NO: 928); G; QGQSGQ (SEQ ID NO: 1196); GQSGQ (SEQ ID NO: 1197);QSGQ (SEQ ID NO: 1198); SGQ (SEQ ID NO: 1198); GQ (SEQ ID NO: 1199); andQ. While the sequences shown below include the spacer sequence of SEQ IDNO: 923, those of ordinary skill in the art will also appreciate thatactivatable anti-PDL1 antibodies of the disclosure in some embodimentsdo not include a spacer sequence.

C5H9v2 VH amino acid sequence (SEQ ID NO: 46)EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRNGIVTVYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWSAAFDYWGQGTLVTVSS[spacer (SEQ ID NO: 929)][PL01-0003 LC (SEQ ID NO: 930)] (SEQ ID NO: 82)[CAAGGTCAGTCTGGATCC][TATTGCGAGGTTAGTGAGCTGTTTGTTCTTCCTTGGTGCATGGGTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL01-0003 LC (SEQ ID NO: 931)] (SEQ ID NO: 83)[QGQSGS][YCEVSELFVLPWCMGGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL01-0003 LC nucleotide sequence (SEQ ID NO: 930)TATTGCGAGGTTAGTGAGCTGTTTGTTCTTCCTTGGTGCATGGGTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL01-0003 LC amino acid sequence(SEQ ID NO: 931)YCEVSELFVLPWCMGGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL02-0003 LC (SEQ ID NO: 932)](SEQ ID NO: 84)[CAAGGTCAGTCTGGATCC][TCTTGCCTTATGCATCCGCATTATGCTCATGATTATTGCTATGTTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL02-0003 LC (SEQ ID NO: 933)] (SEQ ID NO: 85)[QGQSGS][SCLMHPHYAHDYCYVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL02-0003 LC nucleotide sequence (SEQ ID NO: 932)TCTTGCCTTATGCATCCGCATTATGCTCATGATTATTGCTATGTTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL02-0003 LC amino acid sequence(SEQ ID NO: 933)SCLMHPHYAHDYCYVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL03-0003 LC (SEQ ID NO: 934)](SEQ ID NO: 86)[CAAGGTCAGTCTGGATCC][TTGTGCGAGGTTTTGATGTTGTTGCAGCATCCGTGGTGCATGGGGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL03-0003 LC (SEQ ID NO: 935)] (SEQ ID NO: 87)[QGQSGS][LCEVLMLLQHPWCMGGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL03-0003 LC nucleotide sequence (SEQ ID NO: 934)TTGTGCGAGGTTTTGATGTTGTTGCAGCATCCGTGGTGCATGGGGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL03-0003 LC amino acid sequence(SEQ ID NO: 935)LCEVLMLLQHPWCMGGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL04-0003 LC (SEQ ID NO: 936)](SEQ ID NO: 88)[CAAGGTCAGTCTGGATCC][ATTGCGTGCCGGCATTTTATGGAGCAGTTGCCGTTTTGCCATCATGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL04-0003 LC (SEQ ID NO: 937)] (SEQ ID NO: 89)[QGQSGS][IACRHFMEQLPFCKHGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL04-0003 LC nucleotide sequence (SEQ ID NO: 89)ATTGCGTGCCGGCATTTTATGGAGCAGTTGCCGTTTTGCCATCATGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL04-0003 LC amino acid sequence(SEQ ID NO: 937)IACRHFMEQLPFCHHGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL05-0003 LC (SEQ ID NO: 938)](SEQ ID NO: 90)[CAAGGTCAGTCTGGATCC][TTTGGTCCTAGGTGCGGTGAGGCTTCTACTTGCGTTCCGTATGAGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL05-0003 LC (SEQ ID NO: 939)] (SEQ ID NO: 91)[QGQSGS][FGPRCGEASTCVPYEGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL05-0003 LC nucleotide sequence (SEQ ID NO: 938)TTTGGTCCTAGGTGCGGTGAGGCTTCTACTTGCGTTCCGTATGAGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL05-0003 LC amino acid sequence(SEQ ID NO: 939)FGPRCGEASTCVPYEGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL06-0003 LC (SEQ ID NO: 940)](SEQ ID NO: 92)[CAAGGTCAGTCTGGATCC][ATTCTTTATTGCGATAGTTGGGGGGCGGGGTGCTTGACGCGGCCGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL06-0003 LC (SEQ ID NO: 941)] (SEQ ID NO: 93)[QGQSGS][ILYCDSWGAGCLTRPGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL06-0003 LC nucleotide sequence (SEQ ID NO: 940)ATTCTTTATTGCGATAGTTGGGGGGCGGGGTGCTTGACGCGGCCGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL06-0003 LC amino acid sequence(SEQ ID NO: 941)ILYCDSWGAGCLTRPGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL07-0003 LC (SEQ ID NO: 942)](SEQ ID NO: 94)[CAAGGTCAGTCTGGATCC][GGGATTGCGTTGTGCCCGTCTCATTTTTGCCAGCTGCCTCAGACTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL07-0003 LC (SEQ ID NO: 943)] (SEQ ID NO: 95)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-0003 LC nucleotide sequence (SEQ ID NO: 942)GGGATTGCGTTGTGCCCGTCTCATTTTTGCCAGCTGCCTCAGACTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL07-0003 LC amino acid sequence(SEQ ID NO: 943)GIALCPSHFCQLPQTGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL08-0003 LC (SEQ ID NO: 944)](SEQ ID NO: 96)[CAAGGTCAGTCTGGATCC][GATGGGCCGCGTTGCTTTGTGTCGGGGGAGTGCTCTCCGATTGGTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL08-0003 LC (SEQ ID NO: 945)] (SEQ ID NO: 97)[QGQSGS][DGPRCFVSGECSPIGGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL08-0003 LC nucleotide sequence (SEQ ID NO: 944)GATGGGCCGCGTTGCTTTGTGTCGGGGGAGTGCTCTCCGATTGGTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL08-0003 LC amino acid sequence(SEQ ID NO: 945)DGPRCFVSGECSPIGGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYOQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL09-0003 LC (SEQ ID NO: 946)](SEQ ID NO: 98)[CAAGGTCAGTCTGGATCC][TTGTGCTATAAGCTGGATTATGATGATAGGTCTTATTGCCATATTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL09-0003 LC (SEQ ID NO: 947)] (SEQ ID NO: 99)[QGQSGS][LCYKLDYDDRSYCHIGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL09-0003 LC nucleotide sequence (SEQ ID NO: 946)TTGTGCTATAAGCTGGATTATGATGATAGGTCTTATTGCCATATTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL09-0003 LC amino acid sequence(SEQ ID NO: 947)LCYKLDYDDRSYCHIGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL10-0003 LC (SEQ ID NO: 948)](SEQ ID NO: 100)[CAAGGTCAGTCTGGATCC][CCGTGCCATCCGCATCCTTATGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL10-0003 LC (SEQ ID NO: 949)](SEQ ID NO: 101)[QGQSGS][PCHPHPYDARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL10-0003 LC nucleotide sequence (SEQ ID NO: 948)CCGTGCCATCCGCATCCTTATGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL10-0003 LC amino acid sequence(SEQ ID NO: 949)PCHPHPYDARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL11-0003 LC (SEQ ID NO: 950)](SEQ ID NO: 102)[CAAGGTCAGTCTGGATCC][CCTTGCTATTGGCATCCTTTTTTTGCGTATAGGTATTGCAATACTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL11-0003 LC (SEQ ID NO: 951)](SEQ ID NO: 103)[QGQSGS][PCYWHPFFAYRYCNTGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL11-0003 LC nucleotide sequence (SEQ ID NO: 950)CCTTGCTATTGGCATCCTTTTTTTGCGTATAGGTATTGCAATACTGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL11-0003 LC amino acid sequence(SEQ ID NO: 951)PCYWHPFFAYRYCNTGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL12-0003 LC (SEQ ID NO: 952)](SEQ ID NO: 104)[CAAGGTCAGTCTGGATCC][GTTTGCTATTATATGGATTGGTTGGGGCGGAATTGGTGCTCTTCGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL12-0003 LC (SEQ ID NO: 953)](SEQ ID NO: 105)[QGQSGS][VCYYMDWLGRNWCSSGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL12-0003 LC nucleotide sequence (SEQ ID NO: 952)GTTTGCTATTATATGGATTGGTTGGGGCGGAATTGGTGCTCTTCGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL12-0003 LC amino acid sequence(SEQ ID NO: 953)VCYYMDWLGRNWCSSGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL13-0003 LC (SEQ ID NO: 954)](SEQ ID NO: 106)[CAAGGTCAGTCTGGATCC][CTGTGCGATCTGTTTAAGTTGCGTGAGTTTCCTTATTGCATGGGGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL13-0003 LC (SEQ ID NO: 955)](SEQ ID NO: 107)[QGQSGS][LCDLFKLREFPYCMGGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL13-0003 LC nucleotide sequence (SEQ ID NO: 954)CTGTGCGATCTGTTTAAGTTGCGTGAGTTTCCTTATTGCATGGGGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL13-0003 LC amino acid sequence(SEQ ID NO: 955)LCDLFKLREFPYCMGGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYOQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL14-0003 LC (SEQ ID NO: 956)](SEQ ID NO: 108)[CAAGGTCAGTCTGGATCC][TATCTTCCGTGCCATTTTGTTCCGATTGGGGCTTGCAATAATAAGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT[[spacer (SEQ ID NO: 923)][PL14-0003 LC (SEQ ID NO: 957)](SEQ ID NO: 109)[QGQSGS][YLPCHFVPIGACNNKGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL14-0003 LC nucleotide sequence (SEQ ID NO: 956)TATCTTCCGTGCCATTTTGTTCCGATTGGGGCTTGCAATAATAAGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL14-0003 LC amino acid sequence(SEQ ID NO: 957)YLPCHFVPIGACNNKGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL15-0003 LC (SEQ ID NO: 958)](SEQ ID NO: 110)[CAAGGTCAGTCTGGATCC][ATTTTTTGCCATATGGGTGTTGTGGTTCCTCAGTGCGCGAATTATGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL15-0003 LC (SEQ ID NO: 959)](SEQ ID NO: 111)[QGQSGS][IFCHMGVVPQCANYGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL15-0003 LC nucleotide sequence (SEQ ID NO: 958)ATTTTTTGCCATATGGGTGTTGTGGTTCCTCAGTGCGCGAATTATGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL15-0003 LC amino acid sequence(SEQ ID NO: 959)IFCHMGVVVPQCANYGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL16-0003 LC (SEQ ID NO: 960)](SEQ ID NO: 112)[CAAGGTCAGTCTGGATCC][GCGTGCCATCCGCATCCTTATGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL16-0003 LC (SEQ ID NO: 961)](SEQ ID NO: 113)[QGQSGS][ACHPHPYDARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL16-0003 LC nucleotide sequence (SEQ ID NO: 960)GCGTGCCATCCGCATCCTTATGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL16-0003 LC amino acid sequence(SEQ ID NO: 961)ACHPHPYDARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL17-0003 LC (SEQ ID NO: 962)](SEQ ID NO: 114)[CAAGGTCAGTCTGGATCC][CCGTGCCATCCGGCTCCTTATGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL17-0003 LC (SEQ ID NO: 963)](SEQ ID NO: 115)[QGQSGS][PCHPAPYDARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL17-0003 LC nucleotide sequence (SEQ ID NO: 962)CCGTGCCATCCGGCTCCTTATGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL17-0003 LC amino acid sequence(SEQ ID NO: 963)PCHPAPYDARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL18-0003 LC (SEQ ID NO: 964)](SEQ ID NO: 116)[CAAGGTCAGTCTGGATCC][CCGTGCCATCCGCATGCTTATGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL18-0003 LC (SEQ ID NO: 965)](SEQ ID NO: 117)[QGQSGS][PCHPHAYDARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYOQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL18-0003 LC nucleotide sequence (SEQ ID NO: 964)CCGTGCCATCCGCATGCTTATGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL18-0003 LC amino acid sequence(SEQ ID NO: 965)PCHPHAYDARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL19-0003 LC (SEQ ID NO: 966)](SEQ ID NO: 118)[CAAGGTCAGTCTGGATCC][CCGTGCCATCCGCATCCTGCTGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL19-0003 LC (SEQ ID NO: 967)](SEQ ID NO: 119)[QGQSGS][PCHPHPADARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL19-0003 LC nucleotide sequence (SEQ ID NO: 966)CCGTGCCATCCGCATCCTGCTGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL19-0003 LC amino acid sequence(SEQ ID NO: 967)PCHPHPADARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL20-0003 LC (SEQ ID NO: 968)](SEQ ID NO: 120)[CAAGGTCAGTCTGGATCC][CCGTGCCATCCGCATCCTTATGCTGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL2Q-0003 LC (SEQ ID NO: 969)](SEQ ID NO: 121)[QGQSGS][PCHPHPYAARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL20-0003 LC nucleotide sequence (SEQ ID NO: 968)CCGTGCCATCCGCATCCTTATGCTGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL20-0003 LC amino acid sequence(SEQ ID NO: 969)PCHPHPYAARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL21-0003 LC (SEQ ID NO: 970)](SEQ ID NO: 122)[CAAGGTCAGTCTGGATCC][CCGTGCCATCCGCATCCTTATGATGCTGCTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL21-0003 LC (SEQ ID NO: 971)](SEQ ID NO: 123)[QGQSGS][PCHPHPYDAAPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL21-0003 LC nucleotide sequence (SEQ ID NO: 970)CCGTGCCATCCGCATCCTTATGATGCTGCTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL21-0003 LC amino acid sequence(SEQ ID NO: 971)PCHPHPYDAAPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL22-0003 LC (SEQ ID NO: 972)](SEQ ID NO: 124)[CAAGGTCAGTCTGGATCC][CCGTGCCATCCGCATCCTTATGATGCTCGTCCTGCTTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL22-0003 LC (SEQ ID NO: 973)](SEQ ID NO: 125)[QGQSGS][PCHPHPYDARPACNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL22-0003 LC nucleotide sequence (SEQ ID NO: 972)CCGTGCCATCCGCATCCTTATGATGCTCGTCCTGCTTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL22-0003 LC amino acid sequence(SEQ ID NO: 973)PCHPHPYDARPACNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYOQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL23-0003 LC (SEQ ID NO: 974)](SEQ ID NO: 126)[CAAGGTCAGTCTGGATCC][CCGTGCCATCCGCATCCTTATGATGCTCGTCCTTATTGCGCTGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL23-0003 LC (SEQ ID NO: 975)](SEQ ID NO: 127)[QGQSGS][PCHPHPYDARPYCAVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL23-0003 LC nucleotide sequence (SEQ ID NO: 974)CCGTGCCATCCGCATCCTTATGATGCTCGTCCTTATTGCGCTGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL23-0003 LC amino acid sequence(SEQ ID NO: 975)PCHPHPYDARPYCAVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL24-0003 LC (SEQ ID NO: 976)](SEQ ID NO: 128)[CAAGGTCAGTCTGGATCC][CCGTGCCATGCGCATCCTTATGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL24-0003 LC (SEQ ID NO: 977)](SEQ ID NO: 129)[QGQSGS][PCHAHPYDARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL24-0003 LC nucleotide sequence (SEQ ID NO: 976)CCGTGCCATGCGCATCCTTATGATGCTCGTCCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL24-0003 EC amino acid sequence(SEQ ID NO: 977)PCHAHPYDARPYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL25-0003 LC (SEQ ID NO: 978)](SEQ ID NO: 130)[CAAGGTCAGTCTGGATCC][CCGTGCCATCCGCATCCTTATGATGCTCGTGCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL25-0003 LC (SEQ ID NO: 979)](SEQ ID NO: 131)[QGQSGS][PCHPHPYDARAYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL25-0003 LC nucleotide sequence (SEQ ID NO: 978)CCGTGCCATCCGCATCCTTATGATGCTCGTGCTTATTGCAATGTGGGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTACTAGCACCTCTGGTCGTTCCGCTAACCCACGTGGCGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT PL25-0 003 LC amino acid sequence(SEQ ID NO: 979)PCHPHPYDARAYCNVGGGSSGGSGGSGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL03-2001 LC (SEQ ID NO: 980)](SEQ ID NO: 132)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT] [spacer (SEQ ID NO: 923)][PL03-2001 LC (SEQ ID NO: 981)](SEQ ID NO: 133)[QGQSGS][LCEVLMLLQHPWCMGGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQODNGYPSTFGGGTKVEIKR] PL03-2001 LC nucleotide sequence (SEQ ID NO: 980)GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGTPL03-2001 LC amino acid sequence (SEQ ID NO: 981)LCEVLMLLQHPWCMGGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 923)][PL04-2001 LC (SEQ ID NO: 1183)](SEQ ID NO: 1182)[QGQSGS][IACRHFMEQLPFCHHGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL04-2001 LC amino acid sequence(SEQ ID NO: 1183)IACRHFMEQLPFCHHGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL06-2001-mk LC (SEQ ID NO: 982)](SEQ ID NO: 134)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT] [spacer (SEQ ID NO: 923)][PL06-2001-mk LC (SEQ ID NO: 983)](SEQ ID NO: 135)[QGQSGS][ILYCDSWGAGCLTRPGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTOSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL06-2001-mk LC nucleotide sequence(SEQ ID NO: 982)GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGTPL06-2001-mk LC amino acid sequence (SEQ ID NO: 983)ILYCDSWGAGCLTRPGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL07-2001 LC (SEQ ID NO: 984)](SEQ ID NO: 136)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT] [spacer (SEQ ID NO: 923)][PL07-2001 LC (SEQ ID NO: 985)](SEQ ID NO: 137)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2001 LC nucleotide sequence (SEQ ID NO: 984)GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGTPL07-2001 LC amino acid sequence (SEQ ID NO: 985)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL10-2001 LC (SEQ ID NO: 986)](SEQ ID NO: 138)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT] [spacer (SEQ ID NO: 923)][PL10-2001 LC (SEQ ID NO: 987)](SEQ ID NO: 139)[QGQSGS][PCHPHPYDARPYCNVGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL10-2001 LC nucleotide sequence (SEQ ID NO: 986)GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGTPL10-2001 LC amino acid sequence (SEQ ID NO: 987)PCHPHPYDARPYCNVGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 923)][PL11-2001 LC (SEQ ID NO: 1185)](SEQ ID NO: 1184)[QGQSGS][PCYWHPFFAYRYCNTGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL11-2001 LC amino acid sequence(SEQ ID NO: 1185)PCYWHPFFAYRYCNTGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 923)][PL12-2001 LC (SEQ ID NO: 1187)](SEQ ID NO: 1186)[QGQSGS][VCYYMDWLGRNWCSSGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL12-2001 LC amino acid sequence(SEQ ID NO: 1187)VCYYMDWLGRNWCSSGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTOSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL14-2001 LC (SEQ ID NO: 988)](SEQ ID NO: 140)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT] [spacer (SEQ ID NO: 923)][PL14-2001 LC (SEQ ID NO: 989)](SEQ ID NO: 141)[QGQSGS][YLPCHFVPIGACNNKGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL14-2001 LC nucleotide sequence (SEQ ID NO: 988)GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGTPL14-2001 LC amino acid sequence (SEQ ID NO: 989)YLPCHFVPIGACNNKGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL15-2001 LC (SEQ ID NO: 990)](SEQ ID NO: 142)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT] [spacer (SEQ ID NO: 923)][pL15-2001 LC (SEQ ID NO: 991)](SEQ ID NO: 143)[QGQSGS][IFCHMGVVVPQCANYGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL15-2001 LC nucleotide sequence (SEQ ID NO: 990)GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGTPL15-2001 LC amino acid sequence (SEQ ID NO: 991)IFCHMGVVVPQCANYGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQOKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 929)][PL18-2001 LC (SEQ ID NO: 992)](SEQ ID NO: 144)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT] [spacer (SEQ ID NO: 923)][PL18-2001 LC (SEQ ID NO: 993)](SEQ ID NO: 145)[QGQSGS][PCHPHAYDARPYCNVGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQOKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL18-2001 LC nucleotide sequence (SEQ ID NO: 992)GGAGGTGGCTCGAGCGGTGGCAGCGGTGGCTCTGGTGGTATTAGCAGTGGTCTGTTAAGCGGTCGTAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGTPL18-2001 LC amino acid sequence (SEQ ID NO: 993)PCHPHAYDARPYCNVGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 923)][PL19-2001 LC (SEQ ID NO: 1189)](SEQ ID NO: 1188)[QGQSGS][PCHPHPADARPYCNVGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL19-2001 LC amino acid sequence(SEQ ID NO: 1189)PCHPHPADARPYCNVGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 923)][PL20-2001 LC (SEQ ID NO: 1191)](SEQ ID NO: 1190)[QGQSGS][PCHPHPYAARPYCNVGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL20-2001 LC amino acid sequence(SEQ ID NO: 1191)PCHPHPYAARPYCNVGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR[spacer (SEQ ID NO: 929)][PL03-1004/GG/0001 (also referred to hereinas PL03-3001) LC (SEQ ID NO: 994)] (SEQ ID NO: 146)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL03-1004/GG/0001 LC (SEQ ID NO: 995)](SEQ ID NO: 147)[QGQSGS][LCEVLMLLQHPWCMGGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL03-1004/GG/0001 LC nucleotide sequence(SEQ ID NO: 994)GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGTPL03-1004/GG/0001 LC amino acid sequence (SEQ ID NO: 995)LCEVLMLLQHPWCMGGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR[spacer (SEQ ID NO: 929) ][PL06-1004/GG/0001 (also referred to hereinas PL06-3001) LC (SEQ ID NO: 996)] (SEQ ID NO: 148)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGCGAAGTCACCCATCAGGGCCTGAGCTCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGT][spacer (SEQ ID NO: 923)][PL06-1004/GG/0001 LC (SEQ ID NO: 997)](SEQ ID NO: 149)[QGQSGS][ILYCDSWGAGCLTRPGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL06-1004/GG/0001 LC nucleotide sequence(SEQ ID NO: 996)GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGCGAAGTCACCCATCAGGGCCTGAGCTCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGTPL06-1004/GG/0001 LC amino acid sequence (SEQ ID NO: 997)ILYCDSWGAGCLTRPGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR[spacer (SEQ ID NO: 929)][PL07-1004/GG/0001 (also referred to hereinas PL07-3001) LC (SEQ ID NO: 998)] (SEQ ID NO: 150)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGCGAAGTCACCCATCAGGGCCTGAGCTCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGT][spacer (SEQ ID NO: 923)][PL01-1004/GG/0001 LC (SEQ ID NO: 999)](SEQ ID NO: 151)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-1004/GG/0001 LC nucleotide sequence(SEQ ID NO: 998)GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGCGAAGTCACCCATCAGGGCCTGAGCTCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGTPL07-1004/GG/0001 LC amino acid sequence (SEQ ID NO: 999)GIALCPSHFCQLPQTGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR[spacer (SEQ ID NO: 929)][PL14-1004/GG/0001 (also referred to hereinas PL14-3001) LC (SEQ ID NO: 1000)] (SEQ ID NO: 152)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGCGAAGTCACCCATCAGGGCCTGAGCTCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGT][spacer (SEQ ID NO: 923)][PL14-1004/GG/0001 LC (SEQ ID NO: 1001)](SEQ ID NO: 153)[QGQSGS][YLPCHFVPIGACNNKGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTOSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL14-1004/GG/0001 LC nucleotide sequence(SEQ ID NO: 1000)GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGCGAAGTCACCCATCAGGGCCTGAGCTCGCCCGTCACAAAGAGCTTCAACAGGGGAGAGTGTPL14-1004/GG/0001 LC amino acid sequence (SEQ ID NO: 1001)YLPCHFVPIGACNNKGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR[spacer (SEQ ID NO: 929)][PL15-1004/GG/0001 (also referred to hereinas PL15-3001) LC (SEQ ID NO: 1002)] (SEQ ID NO: 154)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL15-1004/GG/0001 LC (SEQ ID NO: 1003)](SEQ ID NO: 155)[QGQSGS][IFCHMGVVVPQCANYGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL15-1004/GG/0001 LC nucleotide sequence(SEQ ID NO: 1002)GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGTPL15-1004/GG/0001 LC amino acid sequence (SEQ ID NO: 1003)IFCHMGVVVPQCANYGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYOQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR[spacer (SEQ ID NO: 929)][PL18-1004/GG/0001 (also referred to hereinas PL18-3001) LC (SEQ ID NO: 1004)] (SEQ ID NO: 156)[CAAGGTCAGTCTGGATCC][GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGT][spacer (SEQ ID NO: 923)][PL18-1004/GG/G001 LC (SEQ ID NO: 1005)](SEQ ID NO: 157)[QGQSGS][PCHPHAYDARPYCNVGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTOSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL18-1004/GG/0001 LC nucleotide sequence(SEQ ID NO: 1004)GGAGGTGGCTCGAGCGGTGGCAGCGGTGCTGTGGGTCTCCTGGCTCCCCCGGGCGGCCTGTCCGGCCGCAGCGATAATCATGGCGGTTCTGACATCCAGATGACCCAGAGCCCCAGCAGCCTGTCTGCTAGCGTGGGCGACAGAGTGACCATCACCTGTAGAGCCAGCCAGAGCATCAGCAGCTACCTGAACTGGTATCAGCAGAAGCCCGGCAAGGCCCCCAAACTGCTGATCTACGCCGCCAGCTCTCTGCAGTCTGGCGTGCCCAGCAGATTTTCCGGCAGCGGCTCTGGCACCGACTTCACCCTGACCATCAGCTCCCTGCAGCCCGAGGACTTCGCCACCTACTACTGCCAGCAGGACAACGGCTACCCCAGCACCTTTGGCGGAGGTACCAAGGTGGAAATCAAGCGTTGTGAGGCCACTCACAAGACATCAACTTCACCCATTGTCAAGAGCTTCAACAGGAATGAGTGTPL18-1004/GG/0001 LC amino acid sequence (SEQ ID NO: 1005)PCHPHAYDARPYCNVGGGSSGGSGAVGLLAPPGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-0001[spacer (SEQ ID NO: 923)][PL07-0001 LC (SEQ ID NO: 1145)](SEQ ID NO: 1144)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-0001 LC amino acid sequence (SEQ ID NO: 1145)GIALCPSHFCQLPQTGGGSSGGSGGSGGLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCOQDNGYPSTFGGGTKVEIKR PL07-0002[spacer (SEQ ID NO: 923)][PL07-0002 LC (SEQ ID NO: 1147)](SEQ ID NO: 1146)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGLSGRSGNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-0002 LC amino acid sequence (SEQ ID NO: 1147)GIALCPSHFCQLPQTGGGSSGGSGGSGGLSGRSGNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-1001[spacer (SEQ ID NO: 923)][PL07-1001 LC (SEQ ID NO: 1149)](SEQ ID NO: 1148)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSSGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-1001 LC amino acid sequence (SEQ ID NO: 1149)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSSGGSDIQMTQSPSSLSASVGDRVTITCRASOSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-1002[spacer (SEQ ID NO: 923)][PL07-1002 LC (SEQ ID NO: 1151)](SEQ ID NO: 1150)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGQNQALRMAGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-1002 LC amino acid sequence (SEQ ID NO: 1151)GIALCPSHFCQLPQTGGGSSGGSGGSGGONQALRMAGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-1003[spacer (SEQ ID NO: 923)][PL07-1003 LC (SEQ ID NO: 1153)](SEQ ID NO: 1152)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGVHMPLGFLGPGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-1003 LC amino acid sequence (SEQ ID NO: 1153)GIALCPSHFCQLPQTGGGSSGGSGGSGGVHMPLGFLGPGGSDIQMTQSPSSLSASVGDRVTITCRASOSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR [spacer (SEQ ID NO: 923)][PL07-1004 LC (SEQ ID NO: 1201)](SEQ ID NO: 1200)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGAVGLLAPPGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-1004 LC amino acid sequence (SEQ ID NO: 1201)GIALCPSHFCQLPQTGGGSSGGSGGSGGAVGLLAPPGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2002[spacer (SEQ ID NO: 923)][PL07-2002 LC (SEQ ID NO: 1155)](SEQ ID NO: 1154)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSGNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2002 LC amino acid sequence(SEQ ID NO: 1155)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSGNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQOKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2003[spacer (SEQ ID NO: 923)][PL07-2003 LC (SEQ ID NO: 1157)](SEQ ID NO: 1156)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2003 LC amino acid sequence(SEQ ID NO: 1157)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2004[spacer (SEQ ID NO: 923)][PL07-2004 LC (SEQ ID NO: 1159)](SEQ ID NO: 1158)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGAVGLLAPPTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2004 LC amino acid sequence(SEQ ID NO: 1159)GIALCPSHFCQLPQTGGGSSGGSGGSGGAVGLLAPPTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2005[spacer (SEQ ID NO: 923)][PL07-2005 LC (SEQ ID NO: 1161)](SEQ ID NO: 1160)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGAVGLLAPPSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2005 LC amino acid sequence(SEQ ID NO: 1161)GIALCPSHFCQLPQTGGGSSGGSGGSGGAVGLLAPPSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2006[spacer (SEQ ID NO: 923)][PL07-2006 LC (SEQ ID NO: 1163)](SEQ ID NO: 1162)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDDHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2006 LC amino acid sequence(SEQ ID NO: 1163)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDDHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2007[spacer (SEQ ID NO: 923)][PL07-2007 LC (SEQ ID NO: 1165)](SEQ ID NO: 1164)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDIHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2007 LC amino acid sequence(SEQ ID NO: 1165)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDIHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2008[spacer (SEQ ID NO: 923)][PL07-2008 LC (SEQ ID NO: 1167)](SEQ ID NO: 1166)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDQHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2008 LC amino acid sequence(SEQ ID NO: 1167)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDQHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2009[spacer (SEQ ID NO: 923)][PL07-2009 LC (SEQ ID NO: 1169)](SEQ ID NO: 1168)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDTHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2009 LC amino acid sequence(SEQ ID NO: 1169)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDTHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2010[spacer (SEQ ID NO: 923)][PL07-2010 LC (SEQ ID NO: 1171)](SEQ ID NO: 1170)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDYHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2010 LC amino acid sequence(SEQ ID NO: 1171)GIALCPSHFCOLPQTGGGSSGGSGGSGGISSGLLSGRSDYHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2011[spacer (SEQ ID NO: 923)][PL07-2011 LC (SEQ ID NO: 1173)](SEQ ID NO: 1172)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDNPGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYOQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2011 LC amino acid sequence(SEQ ID NO: 1173)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDNPGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2012[spacer (SEQ ID NO: 923)][PL07-2012 LC (SEQ ID NO: 1175)](SEQ ID NO: 1174)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSANPGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2012 LC amino acid sequence(SEQ ID NO: 1175)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSANPGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2013[spacer (SEQ ID NO: 923)][PL07-2013 LC (SEQ ID NO: 1177)](SEQ ID NO: 1176)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSANIGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2013 LC amino acid sequence(SEQ ID NO: 1177)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSANIGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-2014[spacer (SEQ ID NO: 923)][PL07-2014 LC (SEQ ID NO: 1179)](SEQ ID NO: 1178)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDNIGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYOQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-2014 LC amino acid sequence(SEQ ID NO: 1179)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDNIGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR PL07-1004/GG/0003[spacer (SEQ ID NO: 923)][PL07-1004/GG/0003 LC (SEQ ID NO: 1181)](SEQ ID NO: 1180)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGAVGLLAPPGGTSTSGRSANPRGGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR] PL07-1004/GG/0003 LC amino acid sequence(SEQ ID NO: 1181)GIALCPSHFCQLPQTGGGSSGGSGGSGGAVGLLAPPGGTSTSGRSANPRGGGSDIQMTOSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKR

Example 11 Anti-PDL1 Activatable Antibodies of the Disclosure

This example demonstrates that anti-PDL1 activatable antibodies can bemade in a variety of combinations of MM, CM, VL, and VH domains as wellas in a variety of distinct human isotypes.

TABLE 18 Anti-PDL1 Activatable Antibody Components Mask SequenceSubstrate Sequence (MM) (CM) VL VH YCEVSELFVLPWCMG LSGRSDNH SEQ ID NO:12 SEQ ID NO: 14 (SEQ ID (SEQ ID NO: 341) NO: 208) SCLMHPHYAHDYCYVTGRGPSWV SEQ ID NO: 58 SEQ ID NO: 16 (SEQ ID (SEQ ID NO: 338) NO: 426)LCEVLMLLQHPWCMG PLTGRSGG SEQ ID NO: 18 (SEQ ID NO: 59) (SEQ ID NO: 344)IACRHFMEQLPFCHH TARGPSFK SEQ ID NO: 20 (SEQ ID NO: 60) (SEQ ID NO: 340)FGPRCGEASTCVPYE NTLSGRSENHSG SEQ ID NO: 22 (SEQ ID NO: 61) (SEQ ID NO:435) ILYCDSWGAGCLTRP NTLSGRSGNHGS SEQ ID NO: 24 (SEQ ID NO: 62) (SEQ IDNO: 436) GIALCPSHFCQLPQT TSTSGRSANPRG SEQ ID NO: 26 (SEQ ID NO: 63) (SEQID NO: 437) DGPRCFVSGECSPIG TSGRSANP SEQ ID NO: 28 (SEQ ID NO: 64) (SEQID NO: 438) LCYKLDYDDRSYCHI VHMPLGFLGP SEQ ID NO: 30 (SEQ ID NO: 65)(SEQ ID NO: 352) PCHPHPYDARPYCNV AVGLLAPP SEQ ID NO: 32 (SEQ ID NO: 66)(SEQ ID NO: 372) PCYWHPFFAYRYCNT AQNLLGMV SEQ ID NO: 34 (SEQ ID NO: 67)(SEQ ID NO: 360) VCYYMDWLGRNWCSS QNQALRMA SEQ ID NO: 36 (SEQ ID NO: 68)(SEQ ID NO: 359) LCDLFKLREFPYCMG LAAPLGLL SEQ ID NO: 38 (SEQ ID NO: 69)(SEQ ID NO: 371) YLPCHFVPIGACNNK STFPFGMF SEQ ID NO: 40 (SEQ ID NO: 70)(SEQ ID NO: 361) IFCHMGVVVPQCANY ISSGLLSS SEQ ID NO: 42 (SEQ ID NO: 71)(SEQ ID NO: 364) ACHPHPYDARPYCNV PAGLWLDP SEQ ID NO: 44 (SEQ ID NO: 72)(SEQ ID NO: 374) PCHPAPYDARPYCNV VAGRSMRP SEQ ID NO: 46 (SEQ ID NO: 73)(SEQ ID NO: 439) PCHPHAYDARPYCNV VVPEGRRS SEQ ID NO: 48 (SEQ ID NO: 74)(SEQ ID NO: 440) PCHPHPADARPYCNV ILPRSPAF SEQ ID NO: 50 (SEQ ID NO: 75)(SEQ ID NO: 441) PCHPHPYAARPYCNV MVLGRSLL SEQ ID NO: 52 (SEQ ID NO: 76)(SEQ ID NO: 442) PCHPHPYDAAPYCNV QGRAITFI SEQ ID NO: 54 (SEQ ID NO: 77)(SEQ ID NO: 443) PCHPHPYDARPACNV SPRSIMLA SEQ ID NO: 56 (SEQ ID NO: 78)(SEQ ID NO: 444) PCHPHPYDARPYCAV SMLRSMPL (SEQ ID NO: 79) (SEQ ID NO:445) PCHAHPYDARPYCNV ISSGLLSGRSDNH (SEQ ID NO: 80) (SEQ ID NO: 377)PCHPHPYDARAYCNV AVGLLAPPGGLSGRSDNH (SEQ ID NO: 81) (SEQ ID NO: 383)ISSGLLSSGGSGGSLSGRSDNH (SEQ ID NO: 378) LSGRSGNH (SEQ ID NO: 883)SGRSANPRG (SEQ ID NO: 884) LSGRSDDH (SEQ ID NO: 885) LSGRSDIH (SEQ IDNO: 886) LSGRSDQH (SEQ ID NO: 887) LSGRSDTH (SEQ ID NO: 888) LSGRSDYH(SEQ ID NO: 889) LSGRSDNP (SEQ ID NO: 890) LSGRSANP (SEQ ID NO: 891)LSGRSANI (SEQ ID NO: 892) LSGRSDNI (SEQ ID NO: 893) MIAPVAYR (SEQ ID NO:894) RPSPMWAY (SEQ ID NO: 895) WATPRPMR (SEQ ID NO: 896) FRLLDWQW (SEQID NO: 897) ISSGL (SEQ ID NO: 898) ISSGLLS (SEQ ID NO: 899) ISSGLL (SEQID NO: 900) ISSGLLSGRSANPRG (SEQ ID NO: 901) AVGLLAPPTSGRSANPRG (SEQ IDNO: 902) AVGLLAPPSGRSANPRG (SEQ ID NO: 903) ISSGLLSGRSDDH (SEQ ID NO:904) ISSGLLSGRSDIH (SEQ ID NO: 905) ISSGLLSGRSDQH (SEQ ID NO: 906)ISSGLLSGRSDTH (SEQ ID NO: 907) ISSGLLSGRSDYH (SEQ ID NO: 908)ISSGLLSGRSDNP (SEQ ID NO: 909) ISSGLLSGRSANP (SEQ ID NO: 910)ISSGLLSGRSANI (SEQ ID NO: 911) AVGLLAPPGGLSGRSDDH (SEQ ID NO: 912)AVGLLAPPGGLSGRSDIH (SEQ ID NO: 913) AVGLLAPPGGLSGRSDQH (SEQ ID NO: 914)AVGLLAPPGGLSGRSDTH (SEQ ID NO: 915) AVGLLAPPGGLSGRSDYH (SEQ ID NO: 916)AVGLLAPPGGLSGRSDNP (SEQ ID NO: 917) AVGLLAPPGGLSGRSANP (SEQ ID NO: 918)AVGLLAPPGGLSGRSANI (SEQ ID NO: 919) ISSGLLSGRSDNI (SEQ ID NO: 920)AVGLLAPPGGLSGRSDNI (SEQ ID NO: 921) GLSGRSDNHGGAVGLLAPP (SEQ ID NO:1009) GLSGRSDNHGGVHMPLGFLGP (SEQ ID NO: 1010)

Any of the combinations described in Table 18 can be combined with humanimmunoglobulin constant regions to result in fully human IgGs includingIgG1, IgG2, IgG4 or mutated constant regions to result in human IgGswith altered functions such as IgG1 N297A, IgG1 N297Q, or IgG4 S228P.The combinations described in Table 18 are not limited by the particularcombinations shown in any given row and include any mask sequence fromcolumn 1 matched with any substrate sequence from column 2 matched withany VL sequence from column 3 matched with any VH sequence from column4. In addition to the substrate sequences disclosed in column 2, any CMdisclosed herein can be used.

As an example, a spacer sequence (SEQ ID NO: 923) and Mask SEQ ID NO: 63can be combined with substrate ISSGLLSGRSDNH (SEQ ID NO: 377), VL SEQ IDNO: 58, and combined with human kappa constant domain to give SEQ ID NO:428; or Mask SEQ ID NO: 63 can be combined with substrate ISSGLLSGRSDNH(SEQ ID NO: 377), VL SEQ ID NO: 58, and combined with human kappaconstant domain to give SEQ ID NO: 1008. Furthermore, VH SEQ ID NO: 46can be combined with human immunoglobulin heavy chain constant domainsto give human IgG1 (SEQ ID NO: 430), mutated human IgG4 S228P (SEQ IDNO: 432), mutated human IgG1 N297A (SEQ ID NO: 434), or mutated humanIgG1 N297Q (SEQ ID NO: 1202). Co-expression of SEQ ID NO: 427 with SEQID NO: 429 will yield a fully human IgG anti-PDL1 activatable antibody.Co-expression of SEQ ID NO: 427 with SEQ ID NO: 431 will yield a fullyhuman IgG4S228P anti-PDL1 activatable antibody. Co-expression of SEQ IDNO: 427 with SEQ ID NO: 433 will yield a fully human IgG1 N297Aanti-PDL1 activatable antibody. Co-expression of SEQ ID NO: 427 with anucleic acid sequence encoding the amino acid sequence of SEQ ID NO:1202 will yield a fully human IgG1 N297Q anti-PDL1 activatable antibody.

[Light chain sequence (SEQ ID NO: 1007) with spacer (SEQ ID NO: 1006)](SEQ ID NO: 427) (SEQ ID NO: 427)[CAGGGCCAGTCCGGCTCA][TATCTGCCCTGCCACTTCGTGCCAATCGGGGCCTGTAACAATAAGGGCGGTGGATCTAGTGGTGGCTCAGGCGGGTCTGGCGGCATTTCCAGTGGACTCTTGTCAGGACGATCCGATAATCATGGCGGGTCCGACATCCAGATGACACAGAGCCCTTCTTCCCTCTCCGCAAGCGTTGGCGACAGGGTCACCATTACCTGTAGGGCTTCTCAGAGCATCTCAAGCTATCTGAACTGGTACCAGCAGAAACCTGGAAAGGCTCCAAAACTGCTGATTTACGCTGCCTCCAGTCTTCAGTCAGGCGTCCCCTCCAGATTTAGCGGATCAGGTAGTGGAACTGATTTTACCCTTACAATATCTTCTCTGCAGCCAGAGGACTTCGCCACATACTATTGTCAGCAAGACAATGGTTACCCCAGTACATTTGGCGGAGGGACAAAGGTCGAGATCAAAAGGACCGTAGCAGCACCAAGCGTCTTTATTTTCCCCCCCAGTGACGAACAGCTGAAGAGCGGAACAGCTTCAGTGGTGTGTCTCCTGAATAACTTCTATCCACGCGAGGCAAAGGTGCAGTGGAAGGTGGACAATGCACTGCAGTCTGGTAATTCCCAAGAAAGTGTTACTGAGCAGGATTCCAAGGATTCAACTTACTCTCTGTCTAGCACCCTGACTCTTTCTAAAGCAGATTATGAGAAGCATAAGGTCTACGCTTGCGAGGTGACCCACCAGGGGCTTTCCTCTCCAGTTACCAAGTCATTCAACCGGGGTGAGTGTTGATGAGAATTC]Light chain sequence without spacer (SEQ ID NO: 1007)TATCTGCCCTGCCACTTCGTGCCAATCGGGGCCTGTAACAATAAGGGCGGTGGATCTAGTGGTGGCTCAGGCGGGTCTGGCGGCATTTCCAGTGGACTCTTGTCAGGACGATCCGATAATCATGGCGGGTCCGACATCCAGATGACACAGAGCCCTTCTTCCCTCTCCGCAAGCGTTGGCGACAGGGTCACCATTACCTGTAGGGCTTCTCAGAGCATCTCAAGCTATCTGAACTGGTACCAGCAGAAACCTGGAAAGGCTCCAAAACTGCTGATTTACGCTGCCTCCAGTCTTCAGTCAGGCGTCCCCTCCAGATTTAGCGGATCAGGTAGTGGAACTGATTTTACCCTTACAATATCTTCTCTGCAGCCAGAGGACTTCGCCACATACTATTGTCAGCAAGACAATGGTTACCCCAGTACATTTGGCGGAGGGACAAAGGTCGAGATCAAAAGGACCGTAGCAGCACCAAGCGTCTTTATTTTCCCCCCCAGTGACGAACAGCTGAAGAGCGGAACAGCTTCAGTGGTGTGTCTCCTGAATAACTTCTATCCACGCGAGGCAAAGGTGCAGTGGAAGGTGGACAATGCACTGCAGTCTGGTAATTCCCAAGAAAGTGTTACTGAGCAGGATTCCAAGGATTCAACTTACTCTCTGTCTAGCACCCTGACTCTTTCTAAAGCAGATTATGAGAAGCATAAGGTCTACGCTTGCGAGGTGACCCACCAGGGGCTTTCCTCTCCAGTTACCAAGTCATTCAACCGGGGTGAGTGTTGATGAGAATTC[Light chain sequence (SEQ ID NO 1008) with spacer (SEQ ID NO: 92)](SEQ ID NO: 428) (SEQ ID NO: 428)[QGQSGS][GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC]Light chain sequence without spacer (SEQ ID NO: 1008)GIALCPSHFCQLPQTGGGSSGGSGGSGGISSGLLSGRSDNHGGSDIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQDNGYPSTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC SEQ ID NO: 429GAAGTGCAGCTGCTCGAAAGCGGCGGAGGCTTGGTGCAGCCAGGAGGGAGCCTGCGACTGTCTTGCGCAGCCAGCGGATTCACTTTCTCTTCCTATGCCATGAGCTGGGTTCGACAGGCACCCGGCAAAGGTCTCGAGTGGGTGTCTAGCATCTGGCGAAACGGAATAGTTACAGTGTATGCCGATAGCGTGAAGGGTCGCTTTACTATTTCACGGGATAATTCTAAGAACACCCTCTACCTGCAAATGAATAGCCTTAGGGCAGAAGATACCGCCGTGTACTACTGTGCCAAATGGTCCGCAGCCTTTGACTACTGGGGCCAGGGGACACTGGTGACCGTGTCCTCTGCATCAACCAAGGGGCCATCAGTGTTCCCACTCGCCCCATCTTCCAAGAGTACTTCCGGCGGAACCGCAGCCCTTGGCTGCCTTGTTAAGGACTATTTCCCAGAACCCGTGACCGTAAGTTGGAACTCTGGCGCCCTTACTTCTGGGGTGCACACCTTCCCAGCAGTGTTGCAGTCCAGTGGCCTTTACTCTCTGTCTAGTGTAGTGACTGTGCCTTCCTCTAGTCTCGGTACCCAGACCTATATTTGTAATGTTAACCATAAGCCCAGCAATACAAAGGTTGATAAGAAAGTGGAACCCAAGAGCTGCGATAAGACACATACCTGCCCACCTTGTCCAGCTCCCGAGCTGCTGGGCGGACCCTCAGTCTTTCTCTTCCCACCTAAACCCAAGGATACCCTTATGATCTCCAGGACTCCTGAGGTGACCTGCGTTGTGGTCGACGTGTCACATGAGGACCCTGAGGTAAAGTTTAACTGGTACGTGGACGGTGTGGAGGTACATAACGCTAAGACTAAGCCACGAGAGGAGCAATACGCTTCCACTTACAGGGTGGTCAGCGTCCTGACCGTTCTCCATCAGGACTGGCTGAACGGGAAGGAATATAAGTGTAAGGTTAGCAACAAAGCTCTCCCTGCACCAATCGAGAAGACAATCAGCAAGGCAAAAGGGCAGCCTCGGGAACCTCAGGTCTACACCCTCCCTCCTAGCAGGGAAGAGATGACAAAGAACCAGGTCTCTCTCACCTGCCTGGTGAAAGGCTTCTATCCATCTGACATTGCTGTGGAGTGGGAATCCAACGGCCAGCCTGAAAATAATTATAAGACCACACCCCCCGTCCTTGATTCCGATGGATCTTTCTTCCTGTACAGTAAACTCACCGTCGACAAATCACGGTGGCAGCAAGGTAACGTGTTCAGCTGTTCTGTCATGCATGAGGCTCTGCATAACCATTACACACAAAAGTCTTTGTCATTGTCTCCAGGATGATGAGAATTCATTGATCATAATCAGCCATACCAC SEQ ID NO: 430EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRNGIVTVYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWSAAFDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG

PPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ ID NO: 431GAAGTGCAGCTGCTCGAAAGCGGCGGAGGCTTGGTGCAGCCAGGAGGGAGCCTGCGACTGTCTTGCGCAGCCAGCGGATTCACTTTCTCTTCCTATGCCATGAGCTGGGTTCGACAGGCACCCGGCAAAGGTCTCGAGTGGGTGTCTAGCATCTGGCGAAACGGAATAGTTACAGTGTATGCCGATAGCGTGAAGGGTCGCTTTACTATTTCACGGGATAATTCTAAGAACACCCTCTACCTGCAAATGAATAGCCTTAGGGCAGAAGATACCGCCGTGTACTACTGTGCCAAATGGTCCGCAGCCTTTGACTACTGGGGCCAGGGGACACTGGTGACCGTGTCCTCTGCATCAACCAAGGGGCCATCAGTGTTCCCACTCGCCCCATGTAGCAGATCAACATCTGAATCCACCGCAGCCCTTGGCTGCCTTGTTAAGGACTATTTCCCAGAACCCGTGACCGTAAGTTGGAACTCTGGCGCCCTTACTTCTGGGGTGCACACCTTCCCAGCAGTGTTGCAGTCCAGTGGCCTTTACTCTCTGTCTAGTGTAGTGACTGTGCCTTCCTCTAGTCTCGGTACCAAGACCTATACCTGCAACGTAGATCATAAGCCCAGCAATACAAAGGTTGATAAGAGAGTAGAGTCAAAGTACGGCCCACCCTGCCCACCTTGTCCAGCTCCCGAGTTCCTGGGCGGACCCTCAGTCTTTCTCTTCCCACCTAAACCCAAGGATACCCTTATGATCTCCAGGACTCCTGAGGTGACCTGCGTTGTGGTCGACGTGTCACAAGAGGACCCTGAGGTACAGTTTAACTGGTACGTGGACGGTGTGGAGGTACATAACGCTAAGACTAAGCCACGAGAGGAGCAATTTAACTCCACTTACAGGGTGGTCAGCGTCCTGACCGTTCTCCATCAGGACTGGCTGAACGGGAAGGAATATAAGTGTAAGGTTAGCAACAAAGGTCTGCCCAGTTCTATCGAGAAGACAATCAGCAAGGCAAAAGGGCAGCCTCGGGAACCTCAGGTCTACACCCTCCCTCCTAGCCAGGAAGAGATGACAAAGAACCAGGTCTCTCTCACCTGCCTGGTGAAAGGCTTCTATCCATCTGACATTGCTGTGGAGTGGGAATCCAACGGCCAGCCTGAAAATAATTATAAGACCACACCCCCCGTCCTTGATTCCGATGGATCTTTCTTCCTGTACAGTCGCCTCACCGTCGACAAATCACGGTGGCAGGAAGGTAACGTGTTCAGCTGTTCTGTCATGCATGAGGCTCTGCATAACCATTACACACAAAAGTCTTTGTCATTGTCTCTCGGATGATGAGAATTCATTGATCATAATCAGCCATACCAC SEQ ID NO: 432EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRNGIVTVYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWSAAFDYWGQGTLVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKV

HNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLG SEQ ID NO: 433GAAGTGCAGCTGCTCGAAAGCGGCGGAGGCTTGGTGCAGCCAGGAGGGAGCCTGCGACTGTCTTGCGCAGCCAGCGGATTCACTTTCTCTTCCTATGCCATGAGCTGGGTTCGACAGGCACCCGGCAAAGGTCTCGAGTGGGTGTCTAGCATCTGGCGAAACGGAATAGTTACAGTGTATGCCGATAGCGTGAAGGGTCGCTTTACTATTTCACGGGATAATTCTAAGAACACCCTCTACCTGCAAATGAATAGCCTTAGGGCAGAAGATACCGCCGTGTACTACTGTGCCAAATGGTCCGCAGCCTTTGACTACTGGGGCCAGGGGACACTGGTGACCGTGTCCTCTGCATCAACCAAGGGGCCATCAGTGTTCCCACTCGCCCCATCTTCCAAGAGTACTTCCGGCGGAACCGCAGCCCTTGGCTGCCTTGTTAAGGACTATTTCCCAGAACCCGTGACCGTAAGTTGGAACTCTGGCGCCCTTACTTCTGGGGTGCACACCTTCCCAGCAGTGTTGCAGTCCAGTGGCCTTTACTCTCTGTCTAGTGTAGTGACTGTGCCTTCCTCTAGTCTCGGTACCCAGACCTATATTTGTAATGTTAACCATAAGCCCAGCAATACAAAGGTTGATAAGAAAGTGGAACCCAAGAGCTGCGATAAGACACATACCTGCCCACCTTGTCCAGCTCCCGAGCTGCTGGGCGGACCCTCAGTCTTTCTCTTCCCACCTAAACCCAAGGATACCCTTATGATCTCCAGGACTCCTGAGGTGACCTGCGTTGTGGTCGACGTGTCACATGAGGACCCTGAGGTAAAGTTTAACTGGTACGTGGACGGTGTGGAGGTACATAACGCTAAGACTAAGCCACGAGAGGAGCAATACGCTTCCACTTACAGGGTGGTCAGCGTCCTGACCGTTCTCCATCAGGACTGGCTGAACGGGAAGGAATATAAGTGTAAGGTTAGCAACAAAGCTCTCCCTGCACCAATCGAGAAGACAATCAGCAAGGCAAAAGGGCAGCCTCGGGAACCTCAGGTCTACACCCTCCCTCCTAGCAGGGAAGAGATGACAAAGAACCAGGTCTCTCTCACCTGCCTGGTGAAAGGCTTCTATCCATCTGACATTGCTGTGGAGTGGGAATCCAACGGCCAGCCTGAAAATAATTATAAGACCACACCCCCCGTCCTTGATTCCGATGGATCTTTCTTCCTGTACAGTAAACTCACCGTCGACAAATCACGGTGGCAGCAAGGTAACGTGTTCAGCTGTTCTGTCATGCATGAGGCTCTGCATAACCATTACACACAAAAGTCTTTGTCATTGTCTCCAGGATGATGAGAATTCATTGATCATAATCAGCCATACCAC SEQ ID NO: 434EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRNGIVTVYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWSAAFDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG

PPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG SEQ ID NO: 1202EVQLLESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKGLEWVSSIWRNGIVTVYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAKWSAAFDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDG

PPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG

Additional examples of heavy chain constant domains include, but are notlimited to, a heavy chain constant region having a mutation or deletionat one or more of the following amino acids: Ser 228, Leu234, Leu235,Gly236, Gly237, Asp265, Asp270, Asn297, Lys 320, Lys 322, Glu328,Pro329, Pro331 as numbered in the EU index as set forth in Kabat, suchthat the Fc domain has less affinity for a Fc-gamma receptor.

Example 12 Evaluation of Efficiency of Masking Moieties

This assay measures the ability of the masking peptide to block bindingof the activatable antibody to antigen as compared to the binding of theunmodified antibody to antigen.

The general outline for this assay is as follows: Nunc, Maxisorp platesare coated overnight at 4° C. with 100 μl/well of a 1 μg/mL solution ofhuman PDL1 (R & D Systems) in PBS, pH 7.4. Plates are washed 3 timeswith PBST (PBS, pH 7.4, 0.05% Tween-20), and wells are blocked with 200ml/well of 10 mg/mL BSA in PBST for 2 hours at RT. Plates are washed 3times with PBST (PBS, pH 7.4, 0.05% Tween-20). Dilution curves areprepared, in 10 mg/mL BSA in PBST, as shown below in Table 10.

TABLE 10 Plate layout for masking efficiency assay, one plate for eachtime point. [activatable [activatable [activatable [Antibody] = antibody1] = antibody 2] = antibody 3] = nM nM nM nM Columns 1-3 Columns 4-6Columns 7-9 Columns 10-12 A 37 1000 1000 1000 B 12.3 333 333 333 C 4.1111 111 111 D 1.34 37 37 37 E 0.45 12.3 12.3 12.3 F 0.15 4.1 4.1 4.1 G0.03 1.34 1.34 1.34 H 0.01 0.45 0.45 Blank

The binding solutions are added to the plates, which are then areincubated for 1 hour at room temperature (RT), and then washed 3 timeswith PBST (PBS, pH 7.4, 0.05% Tween-20). One hundred (100) μl/well1:4000 dilution goat-anti-human IgG (Fab specific, Sigma cat #A0293) in10 mg/mL BSA in PBST is added, and the plate is incubated for 1 hour atRT. The plate is developed with TMB and 1N HCl. Shown in FIGS. 15A, 15B,16A, and 17A are plots of binding isotherms for anti-PDL1 activatableantibodies that include the anti-PDL1 antibody C5H9v2 described herein.Plots are generated in Prizm (Sigma Plot) and the data are fit to amodel of single site saturation and a Kd is determined. In FIG. 17A,PL03+ is an effector positive activatable antibody, namely wild typeIgG1. PL03- is an effector negative activatable antibody, namely mutatedIgG1 N297Q.

Masking efficiency is calculated by dividing the Kd for binding of theactivatable antibodies by the Kd of the parental antibody. Maskingefficiencies are shown in FIGS. 15A, 15B, 16A, AND 17A.

Example 13 Anti-PDL1 Activatable Antibodies of the Disclosure DelayInduction of Diabetes in NOD Mice

In this Example, anti-PDL1 activatable antibodies PL15-0003-C5H9v2 andPL18-0003-C5H9v2 were analyzed for the ability to induce diabetes in NODmice. The NOD mice, substrain NOD/ShiLtJ, were obtained from JacksonLaboratory at 6 weeks and acclimated on site. At 9.5 weeks, mice werechecked for diabetes prior to enrollment, grouped, and dosed as setforth in Table 19.

TABLE 19 Groups and doses for diabetes study with anti-PDL1 activatableantibodies Dose volume Group Count Treatment Dose (mg/kg) (mL/kg)Schedule Route 1 8 mIgG2a (C1.18.4) 3 10 Day 0 IP 2 8 Anti-PDL1 (C5H9v2)1 10 Day 0 IP 3 8 Anti-PDL1 (C5H9v2) 0.3 10 Day 0 IP 4 8 ActivatableAntibody 1 10 Day 0 IP PL15-0003-C5H9v2 5 8 Activatable Antibody 1 10Day 0 IP PL18-0003-C5H9v2

FIG. 18A, which plots % non-diabetic versus number of days post initialdose, shows that anti-PDL1 antibody C5H9v2 induced diabetes in NOD miceat 1 mg/kg while the anti-PDL1 activatable antibody PL15-0003-C5H9v2(labeled herein as Gr4-PF15) did not induce diabetes and the anti-PDL1activatable antibody PL18-0003-C5H9v2 exhibited delayed diabetes at 1mg/kg. Control mIgG2a and anti-PDL1 antibody C5H9v2 at 0.3 mg/kg did notinduce diabetes in NOD mice. In an additional group, a single 3 mg/kgdose of anti-PDL1 activatable antibody PL15-0003-C5H9v2 administered IPat a dose volume of 10 mL/kg induced diabetes in 2 of 8 mice (75%non-diabetic), providing a greater than three-fold safety marginrelative to anti-PDL1 antibody C5H9v2 (Group 2). Results are shown inFIG. 18B.

Example 14 Anti-PDL1 Activatable Antibodies of the Disclosure ReduceMC38 Tumors in Mice

In this Example, anti-PDL1 activatable antibodies PL15-0003-C5H9v2 andPL18-0003-C5H9v2 were analyzed for the ability to reduce the growth ofMC38 syngeneic tumors.

The mouse colon carcinoma cell line MC38 was obtained from ATCC. MC38were grown in RPMI-1640 supplemented with 10% fetal bovine serum at 37°C. in an atmosphere of 5% CO₂ in air. Cells were harvested during thelogarithmic growth period, resuspended in PBS with proper cellconcentration, and kept on ice for tumor induction.

Each mouse was inoculated subcutaneously in the right flank with 0.5×10⁶of MC38 cells in PBS for tumor development. The treatments were startedwhen the mean tumor size reached approximately 100-200 mm³ (no more than200 mm³). Tumor sizes were measured twice weekly in two dimensions usinga caliper, and the volume was expressed in mm³ using the formula: V=0.5a×b² where a and b are the long and short diameters of the tumor,respectively.

The mice were grouped and dosed as set forth in Table 20.

TABLE 20 Groups and doses for MC38 syngeneic study with anti-PDL1activatable antibodies Dose Dose volume Group Count Treatment (mg/kg)(mL/kg) Schedule Route 1 9 mIgG2a 10 10 t.i.w. for 2 IP (C1.18.4) weeks2 9 Anti- 10 10 t.i.w. for 2 IP PDL1 weeks (C5H9v2) 4 9 PL18-0003- 10 10t.i.w. for 2 IP C5H9v2 weeks 6 9 PL15-0003- 10 10 t.i.w. for 2 IP C5H9v2weeks

FIG. 19A, which plots tumor volume versus number of days post initialdose, demonstrates that anti-PDL1 activatable antibodiesPL15-0003-C5H9v2 and PL18-0003-C5H9v2 inhibited the growth of MC38syngeneic tumors similar to positive control anti-PDL1 antibody C5H9v2.

Example 15 An Anti-PDL1 Activatable Antibody of the DisclosureDemonstrates Reduced PDL1 Occupancy in Blood and Spleen from C57Bl/6Mice

Unlike an antibody that would bind target antigen indiscriminately, anactivatable antibody would be a molecule that is inert unless it isactivated in the tumor microenvironment. Once activated, the cleavedactivatable antibody would bind the targeted antigen within the tumoronly, sparing the antigens in the peripheral areas. PDL1 is expressed intumor cells as well as T cells (CD4+ and CD8+) in circulation and thespleen. This example demonstrates that animals treated with anti-PDL1activatable antibody did not have detectable activatable antibody on Tcells in the periphery, while animals treated with anti-PDL1 antibodyshowed a detectable dose dependent presence of antibody on T cells inthe periphery.

To measure whether anti-PDL1 activatable antibody PL15-0003-C5H9v2 isprotected from binding T cells in circulation and the spleen compared tothe anti-PDL1 antibody C5H9v2, 14-week old C57Bl/6 mice (with tumorsranging from 38-671 mm3) were dosed as set forth in Table 21. Tumorsizes were measured in two dimensions using a caliper, and the volumewas expressed in mm³ using the formula: V=0.5 a×b² where a and b are thelong and short diameters of the tumor, respectively. After about 20hours, animals were euthanized; and blood, spleen, and plasma wereharvested from each animal.

TABLE 21 Groups and doses for PDL1 occupancy study Dose Dose volumeSched- Group Count Treatment (mg/kg) (mL/kg) ule Route 1 2 mIgG2a(C1.8.4) 1 10 Day 0 IP 2 2 Anti- 1 10 Day 0 IP PDL1 (C5H9v2) 3 2 Anti-0.3 10 Day 0 IP PDL1 (C5H9v2) 4 2 Anti- 0.1 10 Day 0 IP PDL1 (C5H9v2) 52 PL15-0003- 1 10 Day 0 IP C5H9v2 6 2 PL15-0003- 0.3 10 Day 0 IP C5H9v2

Whole blood was processed as follows: One volume of blood was added to10 volumes of RBC Lysis Solution (130-094-183 Miltenyi Biotec) andprocessed using manufacturer's protocol. Lymphocytes were resuspended instaining buffer (HBSS 2% FBS). Spleen was processed as follows: Spleenwas placed in a 70 uM cell strainer (352350 Corning/BD Falcon) with 1 mLof serum free RPMI-1640. The back of a 3-mL syringe was used to mash thespleen in a circular motion. The strainer was washed with media.Splenocytes were pelleted using a centrifuge and blood was lysed using10 volumes of RBC Lysis Solution (130-094-183 Miltenyi Biotec) accordingto manufacturer's protocol. Splenocytes were refiltered afterresuspending in staining buffer (HBSS 2% FBS). Lymphocytes from wholeblood and lymphocytes from spleen were counted and were aliquoted towells of a 96-well round bottom plates (5e5 cells/well). Cells werepelleted and mouse FcR Reagent was added 1:10 dilution according tomanufacturer's protocol (130-092-575 Miltenyi Biotec). One set of cellswas stained with a saturating amount, 100 nM, of anti-PDL1 antibodyC5H9v2 for 60 minutes to obtain a maximum saturation value. Cells werewashed 3 times and are stained with a biotinylated ‘a’ allotypeantibody, anti-mIgG2a (a) clone 8.3 (553502 BD Biosciences) at 300 ng/mLfor 60 minutes. Cells were washed 3 times and then stained with 1 ug/mL(also referred to herein as “μg/mL”) of anti-CD4-Pacific Blue (558107 BDBioscience), 1 ug/mL of anti-CD8-APC (553035 BD Bioscience) and 1:500dilution of SAPE (S-866 Life Technologies) for 30 minutes. Cells werewashed 2 times and stained with 7-AAD according to manufacturer'sprotocol (559925 BD Bioscience). The MACSQuant flow cytometer was usedto measure the amount of anti-PDL1 antibody C5H9v2 and anti-PDL1activatable antibody PL15-0003-C5H9v2 bound to T cells from whole bloodand the spleen. Briefly, at the most 30,000 events were collected in thelymphocyte gate. Live cells were gated from the 7AAD negative gate. CD4+and CD8+ cells were gated separately and anti-PDL1 mAb and anti-PDL1activatable antibody MFI were recorded for both CD4 and CD8. Percentoccupancy was determined by taking the MFI of the sample compared to theaverage of the MFI for the maximum binding MFI. FIGS. 20A-20Ddemonstrate the percent of anti-PDL1 antibody C5H9v2 and anti-PDL1activatable antibody PL15-0003-C5H9v2 bound to CD4+ and CD8+ T cellsfrom peripheral blood (FIGS. 20A, 20B) or spleen (FIGS. 20C, 20D). Inall graphs, the circle represents isotype, the square representsanti-PDL1 antibody C5H9v2, and the triangle represents anti-PDL1activatable antibody PL15-0003-C5H9v2. Percent occupancy of theanti-PDL1 antibody C5H9v2 was reflective of the dose titration. Percentoccupancy of the anti-PDL1 activatable antibody PL15-0003-C5H9v2 at 1mg/kg was similar to isotype control mIgG2a at 1 mg/kg.

Example 16 An Anti-PDL1 Activatable Antibody of the DisclosureDemonstrates Reduced PDL1 Occupancy in Blood and Spleen from C57Bl/6Mice

This example demonstrates that animals treated with an anti-PDL1activatable antibody of the disclosure exhibited reduced binding toblood T cells from tumor bearing mice compared to that exhibited by ananti-PDL1 antibody of the disclosure at a variety of doses.

The study was conducted in a manner similar to that described in Example15. Briefly, mice bearing MC38 tumors between 100-200 mm³ were treatedwith a single dose of anti-PDL1 antibody C5H9v2 or anti-PDL1 activatableantibody PL15-0003-C5H9v2 as indicated in FIGS. 21A and 21B, and bloodwas analyzed for surface bound antibody by flow cytometry four daysafter dosing. Plasma concentrations of the antibody and activatableantibody were determined by ELISA. FIGS. 21A and 21 B demonstrate thatthe presence of tumor-derived proteases capable of cleaving theactivatable antibody did not lead to high levels of activatedactivatable antibody in the blood (FIG. 21A); i.e., the activatableantibody (depicted by squares) demonstrated reduced peripheral PDL1binding in tumor-bearing mice compared to the antibody (depicted bycircles) or an isotype antibody (depicted by triangles) despite theplasma concentrations of the activatable antibody being higher thanthose of the antibody (FIG. 21B).

Example 17 Activity of an Anti-PDL1 Antibody and an Anti-PDL1Activatable Antibody of the Embodiments in a Human T-Cell RestimulationAssay

In this example, peripheral blood mononuclear cells from a CMV-positivedonor were incubated in the presence of CMV viral lysate and ananti-PDL1 antibody or an anti-PDL1 activatable antibody of thedisclosure to assess the effect of such anti-PDL1 antibody or anti-PDL1activatable antibody on interferon gamma (IFN-gamma) cytokine secretion.

PBMCs from a CMV-positive donor (Hemacare Donor C) were plated at3.5×10⁵ cells per well in the presence of 4 μg/mL CMV viral lysate(Astarte) and either anti-PDL1 antibody C5H9v2, anti-PDL1 activatableantibody PL07-2001-C5H9v2, or an hIgG4 isotype control antibody. Afterfour days, supernatant was removed from each well and IFN-gamma levelswere assayed using IFN-gamma ELISA kit (Life Technologies, Carlsbad,Calif.). FIG. 22A demonstrates that anti-PDL1 activatable antibodyPL07-2001-C5H9v2 exhibited increased CMV-stimulated IFN-gamma secretioncompared with control hIgG4 but decreased potency relative to anti-PDL1parental antibody C5H9v2 due to the activatable antibody being masked.

Example 18 In Situ Imaging of an Anti-PDL1 Activatable Antibody of theDisclosure

This Example demonstrates the ability of anti-PDL1 activatable antibodyPL15-0003-C5H9v2 to be activated and to bind frozen MC38 mouse cancertissues using an in situ imaging method.

Fluorescently-labeled anti-PDL1 activatable antibody PL15-0003-C5H9v2 oranti-PDL1 antibody C5H9v2 was incubated on frozen PDL1+MC38 tumorsections for 1 hour in a protease-compatible buffer in the presence orabsence of a broad spectrum inhibitor cocktail as described in PCTInternational publication number WO 2014/107599, published Jul. 10,2014.

Results are shown in FIGS. 23A-23D. The tissue image in FIG. 23Ademonstrates binding of anti-PDL1 antibody C5H9v2 to the tumor sectionindicating the presence of PDL1 antigen in the tumor section. The tissueimage in FIG. 23B demonstrates that anti-PDL1 activatable antibodyPL5-0003-C5H9v2 was activated by tumor-derived proteolytic cleavage ofthe anti-PDL1 activatable antibody to yield an anti-PDL1 antibody thatbound to the PDL1 target in the tumor section. The tissue image in FIG.23D demonstrates that the fluorescent signal shown in FIG. 23B wasinhibited by pre-treatment of the tumor section with a 1:100 dilution ofbroad spectrum inhibitor cocktail set III and 50 mM EDTA, whereas noeffect of broad spectrum protease inhibitors was detected on the bindingof anti-PDL1 antibody C5H9v2 to the tumor section as demonstrated in thetissue image in FIG. 23C. These results demonstrate that the tumorsections comprise sufficient protease activity to activate activatableantibodies of the disclosure.

Example 19 Ability of an Activatable Antibody of the Disclosure toDemonstrate Protease-Dependent Binding and Blocking Activity In Vitro

This Example demonstrates the ability anti-PDL1 activatable antibodyPL15-0003-C5H9v2 to exhibit protease-dependent binding and blockingactivity in vitro.

Binding and blocking studies were conducted on anti-PDL1 antibody C5H9v2and anti-PDL1 activatable antibody PL15-0003-C5H9v2 in a manner similarto those described elsewhere in the Examples except that plates werecoated with 0.5 μg/mL PDL1.

FIG. 24A depicts that anti-PDL1 activatable antibody PL15-0003-C5H9v2exhibited a higher EC₅₀ for PDL1 binding and PD1 blocking than did theanti-PDL1 antibody as measured by ELISA. The figure further demonstratesthat activation of anti-PDL1 activatable antibody PL15-0003-C5H9v2 bymatriptase fully restored PDL1 binding and PD1 blocking activities tolevels comparable to those of anti-PDL1 antibody C5H9v2.

Example 20 Ability of an Anti-PDL1 Activatable Antibody of theDisclosure to Reduce Binding to PDL1 and to DemonstrateProtease-Dependent Blocking Activity In Vitro

This Example measures the ability of a masking peptide to reduce bindingof an anti-PDL1 activatable antibody of the disclosure to PDL1 comparedto the ability of the parental antibody to bind to PDL1 in vitro. ThisExample also demonstrates the ability of an anti-PDL1 activatableantibody of the disclosure to exhibit protease-dependent blockingactivity in vitro.

The abilities of anti-PDL1 activatable antibodies PL07-2001-C5H9v2 andPF07-3001-C5H9v2 and anti-PDL1 antibody C5H9 to bind to human or murinePDL1 were tested in a manner similar to techniques described elsewherein the Examples. Results are shown in FIGS. 25A and B.

The abilities of anti-PDL1 activatable antibody PL07-2001-C5H9v2,uPA-activated anti-PDL1 activatable antibody PL07-2001-C5H9v2,MMP14-activated anti-PDL1 activatable antibody PL07-2001-C5H9v2, andanti-PDL1 antibody C5H9v2 to block PD1 (PD-1) or B7-1 binding to PDL1were tested in a manner similar to techniques described elsewhere in theExamples.

Briefly, for the PD1 blockade assay, human, cyno or rat PDL1 wasadsorbed to the well of an ELISA plate. Biotinylated human, cyno, or ratPD1 was applied to the wells in the absence or presence of an increasingconcentration of either anti-PDL1 activatable antibody PL07-2001-C5H9v2,uPA-activated anti-PDL1 activatable antibody PL07-2001-C5H9v2,MMP14-activated anti-PDL1 activatable antibody PL07-2001-C5H9v2, oranti-PDL1 antibody C5H9v2. Results, shown in FIGS. 26A to C, indicatethat activatable antibody PF07-2001-C5H9v2 exhibited a higher EC₅₀ forPD1 blocking than did the anti-PDL1 antibody as measured by ELISA.However, activation of the activatable antibody by either uPA or MMP14restored PD1 blocking activity to levels comparable to those ofanti-PDL1 antibody C5H9v2.

Briefly, for the B7-1 blockade assay, human or cyno PDL1 was adsorbed tothe well of an ELISA plate. Biotinylated human or cyno B7-1 was appliedto the wells in the absence or presence of an increasing concentrationof either anti-PDL1 activatable antibody PL07-2001-C5H9v2, uPA-activatedanti-PDL1 activatable antibody PL07-2001-C5H9v2, MMP14-activatedanti-PDL1 activatable antibody PL07-2001-C5H9v2, or anti-PDL1 antibodyC5H9v2. Results, shown in FIGS. 27A and B, indicate that activatableantibody PF07-2001-C5H9v2 exhibited a higher EC₅₀ for B7-1 blocking thandid the anti-PDL1 antibody as measured by ELISA. However, activation ofthe activatable antibody by either uPA or MMP14 restored B7-1 blockingactivity to levels comparable to those of anti-PDL1 antibody C5H9v2.

Example 21 Anti-PDL1 Activatable Antibodies of the Disclosure ReduceMC38 Tumors in Mice

In this Example, anti-PDL1 activatable antibodies PL15-0003-C5H9v2,PL15-2001-C5H9v2, and PL15-3001-C5H9v2 were analyzed for the ability toreduce the growth of MC38 syngeneic tumors.

The mouse colon carcinoma cell line MC38 was obtained from ATCC. MC38were grown in RPMI-1640 supplemented with 10% fetal bovine serum at 37°C. in an atmosphere of 5% CO₂ in air. Cells were harvested during thelogarithmic growth period, resuspended in PBS with proper cellconcentration, and kept on ice for tumor induction.

Each mouse was inoculated subcutaneously in the right flank with 0.5×10⁶of MC38 cells in PBS for tumor development. The treatments were startedwhen the mean tumor size reached approximately 100-200 mm³ (no more than200 mm³). Tumor sizes were measured twice weekly in two dimensions usinga caliper, and the volume was expressed in mm³ using the formula: V=0.5a×b² where a and b are the long and short diameters of the tumor,respectively.

The mice were grouped and dosed as set forth in Table 24.

TABLE 24 Groups and doses for MC38 syngeneic study with anti-PDL1activatable antibodies Dose Dose volume Group Count Treatment (mg/kg)(mL/kg) Schedule Route 1 9 mIgG2a (C1.18.4) 5 10 b.i.w.; 4 doses IP 2 9Anti-PDL1 (C5H9v2) 5 10 b.i.w.; 4 doses IP 3 9 PL15-0003-C5H9v2 5 10b.i.w.; 4 doses IP 4 9 PL15-2001-C5H9v2 5 10 b.i.w.; 4 doses IP 5 9PL15-3001-C5H9v2 5 10 b.i.w.; 4 doses IP

FIG. 28A, which plots tumor volume versus number of days post initialdose, demonstrates that anti-PDL1 activatable antibodiesPL15-0003-C5H9v2, PL15-2001-C5H9v2, and PL15-3001-C5H9v2 inhibited thegrowth of MC38 syngeneic tumors similar to positive control anti-PDL1antibody C5H9v2.

Example 22 An Anti-PDL1 Activatable Antibody of the DisclosureDemonstrates Reduced PDL1 Occupancy in Blood from C57Bl/6 Mice

This example demonstrates that animals treated with anti-PDL1activatable antibodies of the disclosure exhibited reduced binding toblood T cells from tumor bearing mice compared to that exhibited by ananti-PDL1 antibody of the disclosure.

The study was conducted in a manner similar to that described in Example15. Briefly, mice bearing MC38 tumors between 100-200 mm³ were treatedwith a single dose of anti-PDL1 antibody C5H9v2 or anti-PDL1 activatableantibody PL15-0003-C5H9v2, PL15-2001-C5H9v2, or PL15-3001-C5H9v2 asindicated in Table 25, and blood was analyzed for surface bound antibodyby flow cytometry four and eight days after dosing. Percent occupancywas calculated as described in Example 15.

TABLE 25 Groups and doses for PDL1 occupancy study Dose Dose volumeGroup Count Treatment (mg/kg) (mL/kg) Schedule Route 1 9 mIgG2a(C1.18.4) 5 10 b.i.w.; 4 doses IP 2 9 Anti-PD-L1 (C5H9v2) 5 10 b.i.w.; 4doses IP 3 9 Anti-PD-L1 (C5H9v2) 3 10 b.i.w.; 4 doses IP 4 9PL15-0003-C5H9v2 5 10 b.i.w.; 4 doses IP 5 9 PL15-0003-C5H9v2 3 10b.i.w.; 4 doses IP 6 9 PL15-2001-C5H9v2 5 10 b.i.w.; 4 doses IP 7 9PL15-2001-C5H9v2 3 10 b.i.w.; 4 doses IP 8 9 PL15-3001-C5H9v2 5 10b.i.w.; 4 doses IP 9 9 PL15-3001-C5H9v2 3 10 b.i.w.; 4 doses IP

Plasma concentrations of the antibody and activatable antibodies weredetermined by ELISA. FIGS. 29A to C demonstrate that the presence oftumor-derived proteases capable of cleaving the activatable antibodiesdid not lead to high levels of activated activatable antibodies in theblood.

Example 23 In Vivo Imaging of an Anti-PDL1 Activatable Antibody of theDisclosure

This Example demonstrates the ability of proteases in a tumor implantedinto a mouse to activate an anti-PDL1 activatable antibody of thedisclosure.

A MDA-MB-231-luc2 orthotopic xenograft breast cancer model was used forthese studies. Female nu/nu mice were purchased from Charles RiverLaboratories to arrive at 7 week old. After 1 week acclimation, threemillion MDA-MD-231-luc2-4D3LN cells (Perkin Elmer) in 30 microliters(ul, also referred to herein as “μl”) serum-free RPMI (1:1 matrigel)were injected into the fourth abdominal left mammary fat pad. Tumorswere grown to 110-159 mm³. Three mice per group were administeredintravenously 5 mg/kg Alexa750-conjugated anti-PDL1 antibody C5H9v2 oranti-PDL1 activatable antibody PL07-2001-C5H9v2. Four mice wereadministered intravenously 5 mg/kg Alexa750-conjugated anti-RSV antibodycontrol palivizumab (Synagis). Ninety-six hours after administration,optical images were collected from each of the mice. Results are shownin FIG. 30A. A high-intensity fluorescent signal was detected only inthe tumors of mice dosed with the anti-PDL1 antibody or anti-PDL1activatable antibody PL07-2001-C5H9v2, suggesting that the anti-PDL1activatable antibody was activated and accumulated in the tumor throughPDL1 binding.

Example 24 Activation of an Activatable Antibody of the Disclosure inHuman Plasma Samples

This Example determines whether an activatable antibody of thedisclosure is activated in human plasma samples.

Anti-PDL1 activatable antibody PL07-2001-C5H9v2 was conjugated withOregon Green dye (ThermoFisher Cat#O6149). The concentration and degreeof labeling was determined with a spectrophotometer. Three uM (alsoreferred to herein as “μM”) of labeled anti-PDL1 activatable antibodyPL07-2001-C5H9v2 was added into plasma samples obtained from healthydonors, patients with melanoma or lung cancer patients in a finalactivatable antibody to plasma ratio of 30:70. The samples wereincubated for 48 hours in a 37° C. humidifying chamber. Reactions oflabeled anti-PDL1 activatable antibody PL07-2001-C5H9v2 in plasma werestopped at either 0 or 48 hours by freezing samples in −80° C. ordenaturing in Wes running buffer (ProteinSimple Cat #PS-MK14). Sampleswere analyzed by the Wes capillary western blot system (ProteinSimple)using antibodies against Oregon Green dye (ThermoFisher Cat#A-11095 at100 μg/ml) followed by HRP conjugated secondary antibody (JacksonImmunoResearch Cat#705-035-147 at 1/40 dilution). Analysis of percentactivation of the labeled anti-PDL1 activatable antibodyPL07-2001-C5H9v2 was determined using Compass (ProteinSimple) software.

There was no detectable activatable antibody activation in five normalpatient samples, in five melanoma patient samples (three metastases inlymph nodes, two in the brain, and one on the skin of the back), nor infive lung cancer patient samples (one metastasis in the lower lobe ofthe left lung (stage IV), one in the lower lobe of the right lung (stageIV), one in the upper lobe of the left lung (stage IA), and two in theupper lobe of the right lung (stages IIIA and IB).

OTHER EMBODIMENTS

While the invention has been described in conjunction with the detaileddescription thereof, the foregoing description is intended to illustrateand not limit the scope of the invention, which is defined by the scopeof the appended claims. Other aspects, advantages, and modifications arewithin the scope of the following.

1. An isolated antibody or antigen binding fragment thereof (AB) that specifically binds to mammalian PDL1, wherein the AB has one or more of the following characteristics: (a) the AB specifically binds to human PDL1 and murine PDL1; (b) the AB specifically binds to human PDL1 and cynomolgus monkey PDL1; (c) the AB specifically binds to human PDL1, murine PDL1, and cynomolgus monkey PDL1; (d) the AB inhibits binding of human B7-1 and human PD1 to human PDL1 with an EC₅₀ value less than 10 nM; (e) the AB inhibits binding of murine B7-1 and murine PD1 to murine PDL1 with an EC₅₀ value less than 10 nM; and (f) the AB inhibits binding of cynomolgus monkey B7-1 and cynomolgus monkey PD1 to cynomolgus monkey PDL1 with an EC₅₀ value less than 10 nM.
 2. An activatable antibody that, in an activated state, specifically binds to mammalian PDL1, wherein said activatable antibody comprises: an antibody or an antigen binding fragment thereof (AB) that specifically binds to mammalian PDL1; a masking moiety (MM) that inhibits the binding of the AB to mammalian PDL1 when the activatable antibody is in an uncleaved state; and a cleavable moiety (CM) coupled to the AB, wherein the CM is a polypeptide that functions as a substrate for a protease.
 3. The activatable antibody of claim 2, wherein the activatable antibody, in an activated state, specifically blocks a natural ligand of PDL1 from binding to the mammalian PDL1.
 4. The activatable antibody of claim 2, wherein the activatable antibody has one or more of the following characteristics selected from the group consisting of: (i) the activatable antibody in an uncleaved state specifically binds to the mammalian PDL1 with a dissociation constant of (a) 1 to 2 nM, 1 to 5 nM, 1 to 10 nM, 1 to 15 nM, 1 to 20 nM, 1 to 25 nM, (b) 2 nM to 5 nM, 2 nM to 10 nM, 2 nM to 15 nM, 2 to 20 nM, 2 to 25 nM, (c) 5 nM to 10 nM, 5 nM to 15 nM, 5 to 20 nM, 5 to 25 nM, (d) 10 nM to 15 nM, 10 to 20 nM, 10 to 25 nM, (e) 15 to 20 nM, 15 to 25 nM, or (f) 20 to 25 nM; (ii) the activatable antibody in an activated state specifically binds to the mammalian PDL1 with a dissociation constant of (a) 0.01 nM to 1 nM, 0.05 nM to 1 nM, 0.1 nM to 1 nM, 0.2 nM to 1 nM, 0.3 nM to 1 nM, 0.4 nM to 1 nM, 0.5 nM to 1 nM, 0.75 nM to 1 nM, (b) 0.01 nM to 0.75 nM, 0.05 nM to 0.75 nM, 0.1 nM to 0.75 nM, 0.2 nM to 0.75 nM, 0.3 nM to 0.75 nM, 0.4 nM to 0.75 nM, 0.5 nM to 0.75 nM, (c) 0.01 nM to 0.5 nM, 0.05 nM to 0.5 nM, 0.1 nM to 0.5 nM, 0.2 nM to 0.5 nM, 0.3 nM to 0.5 nM, 0.4 nM to 0.5 nM, (d) 0.01 nM to 0.4 nM, 0.05 nM to 0.4 nM, 0.1 nM to 0.4 nM, 0.2 nM to 0.4 nM, 0.3 nM to 0.4 nM, (e) 0.01 nM to 0.3 nM, 0.05 nM to 0.3 nM, 0.1 nM to 0.3 nM, 0.2 nM to 0.3 nM, (f) 0.01 nM to 0.2 nM, 0.05 nM to 0.2 nM, 0.1 nM to 0.2 nM, (g) 0.01 nM to 0.1 nM, 0.05 nM to 0.1 nM, or (h) 0.01 nM to 0.05 nM; and (iii) the activatable antibody comprises an AB that specifically binds to the mammalian PDL1 with a dissociation constant of (a) 0.01 nM to 1 nM, 0.05 nM to 1 nM, 0.1 nM to 1 nM, 0.2 nM to 1 nM, 0.3 nM to 1 nM, 0.4 nM to 1 nM, 0.5 nM to 1 nM, 0.75 nM to 1 nM, (b) 0.01 nM to 0.75 nM, 0.05 nM to 0.75 nM, 0.1 nM to 0.75 nM, 0.2 nM to 0.75 nM, 0.3 nM to 0.75 nM, 0.4 nM to 0.75 nM, 0.5 nM to 0.75 nM, (c) 0.01 nM to 0.5 nM, 0.05 nM to 0.5 nM, 0.1 nM to 0.5 nM, 0.2 nM to 0.5 nM, 0.3 nM to 0.5 nM, 0.4 nM to 0.5 nM, (d) 0.01 nM to 0.4 nM, 0.05 nM to 0.4 nM, 0.1 nM to 0.4 nM, 0.2 nM to 0.4 nM, 0.3 nM to 0.4 nM, (e) 0.01 nM to 0.3 nM, 0.05 nM to 0.3 nM, 0.1 nM to 0.3 nM, 0.2 nM to 0.3 nM, (f) 0.01 nM to 0.2 nM, 0.05 nM to 0.2 nM, 0.1 nM to 0.2 nM, (g) 0.01 nM to 0.1 nM, 0.05 nM to 0.1 nM, or (h) 0.01 nM to 0.05 nM. 5.-6. (canceled)
 7. The activatable antibody of claim 2, wherein the mammalian PDL1 has one or more of the following characteristics selected from the group consisting of: (i) the mammalian PDL1 is selected from the group consisting of a human PDL1, a murine PDL1, a rat PDL1, and a cynomolgus monkey PDL1; and (ii) the mammalian PDL1 is a human PDL1.
 8. The activatable antibody of claim 2, wherein the AB has one or more of the following characteristics selected from the group consisting of: (i) the AB specifically binds to human PDL1, murine PDL1 or cynomolgus monkey PDL1 with a dissociation constant of less than 1 nM; (ii) the AB specifically binds to human PDL1 and murine PDL1; (iii) the AB specifically binds to human PDL1 and cynomolgus monkey PDL1; (iv) the AB specifically binds to human PDL1, murine PDL1, and cynomolgus monkey PDL1; (v) the AB inhibits binding of human B7-1 and human PD1 to human PDL1; (vi) the AB inhibits binding of murine B7-1 and murine PD1 to murine PDL1; and (vii) the AB inhibits binding of cynomolgus monkey B7-1 and cynomolgus monkey PD1 to cynomolgus monkey PDL1. 9.-11. (canceled)
 12. The activatable antibody of claim 2, wherein the AB blocks the ability of a natural ligand to bind to the mammalian PDL1 with an EC₅₀ of (a) 0.5 nM to 10 nM, 0.5 nM to 5 nM, 0.5 nM to 3 nM, 0.5 nM to 2 nM, 0.5 nM to 1 nM, (b) 1 nM to 10 nM, 1 nM to 5 nM, 1 nM to 3 nM, 1 nM to 2 nM, (c) 2 nM to 10 nM, 2 nM to 5 nM, 2 nM to 3 nM, (d) 3 nM to 10 nM, 3 nM to 5 nM, or (e) 5 nM to 10 nM.
 13. The activatable antibody of claim 12, wherein the natural ligand has one or more of the following characteristics selected from the group consisting of: (i) the natural ligand is a mammalian PD1; (ii) the natural ligand is selected from the group consisting of: a human PD1, a murine PD1, and a cynomolgus monkey PD1; (iii) the natural ligand is a mammalian B7-1; and (iv) the natural ligand is selected from the group consisting of: a human B7-1, a murine B7-1, and a cynomolgus monkey B7-1. 14.-16. (canceled)
 17. The activatable antibody of claim 2, wherein: (a) the AB induces type 1 diabetes in a non-obese diabetic (NOD) mouse; and (b) the activatable antibody in an uncleaved state inhibits the induction of type 1 diabetes in a NOD mouse.
 18. The activatable antibody of claim 17, wherein the activatable antibody inhibits the induction of type 1 diabetes in the NOD mouse after administration of the activatable antibody at a single dose of (a) 0.1 mg/kg to 3 mg/kg, 0.5 mg/kg to 3 mg/kg, 1 mg/kg to 3 mg/kg, 2 mg/kg to 3 mg/kg, (b) 0.1 mg/kg to 2 mg/kg, 0.5 mg/kg to 2 mg/kg, 1 mg/kg to 2 mg/kg, (c) 0.1 mg/kg to 1 mg/kg, 0.5 mg/kg to 1 mg/kg, or (d) 0.1 mg/kg to 0.5 mg/kg.
 19. The activatable antibody of claim 2, wherein: (a) the activatable antibody in an uncleaved state does not induce type 1 diabetes in greater than 50% of a population of non-obese diabetic (NOD) mice, and (b) the AB induces type 1 diabetes in greater than 50% of a population of NOD mice.
 20. The activatable antibody of claim 19, wherein the activatable antibody does not induce type 1 diabetes in greater than 50% of the population of NOD mice after administration to each mouse in the population a single dose of the activatable antibody at a dosage of: (a) 0.1 mg/kg to 3 mg/kg, 0.5 mg/kg to 3 mg/kg, 1 mg/kg to 3 mg/kg, 2 mg/kg to 3 mg/kg, (b) 0.1 mg/kg to 2 mg/kg, 0.5 mg/kg to 2 mg/kg, 1 mg/kg to 2 mg/kg, (c) 0.1 mg/kg to 1 mg/kg, 0.5 mg/kg to 1 mg/kg, or (d) 0.1 mg/kg to 0.5 mg/kg.
 21. The activatable antibody of claim 19, wherein: (a) the activatable antibody in an uncleaved state does not induce type 1 diabetes in greater than 50% of a population of non-obese diabetic (NOD) mice when administered at a single dose of 1 mg/kg; and (b) the AB induces type 1 diabetes in greater than 50% of a population of NOD mice, when administered at a single dose of 1 mg/kg.
 22. The activatable antibody of claim 17, wherein the NOD mouse is a female NOD/ShiLtJ mouse substrain.
 23. The activatable antibody of claim 17, wherein the activatable antibody has one or more of the following characteristics selected from the group consisting of: (i) the activatable antibody inhibits the induction of type 1 diabetes in a NOD mouse by at least 3-fold compared to the AB; and (ii) the activatable antibody exhibits a safety margin that is at least a three-fold safety margin relative to the AB.
 24. (canceled)
 25. The activatable antibody of claim 2, wherein the activatable antibody in an uncleaved state binds to a smaller percentage of a population of peripheral blood CD4+ CD8+ T lymphocytes than does the AB.
 26. The activatable antibody of claim 25, wherein the peripheral blood CD4+ CD8+ T lymphocytes are murine.
 27. The activatable antibody of claim 26, wherein the murine peripheral blood CD4+ CD8+ T lymphocytes are derived from a tumor-bearing mouse.
 28. The activatable antibody of claim 2, wherein the activatable antibody has one or more of the following characteristics selected from the group consisting of: (i) the AB comprises: (a) a variable heavy chain complementarity determining region 1 (VH CDR1) comprising the amino acid sequence of SEQ ID NO: 212; (b) a variable heavy chain complementarity determining region 2 (VH CDR2) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 213, 217, 221, 225, 229, 231, and 238-247; (c) a variable heavy chain complementarity determining region 3 (VH CDR3) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 214, 218, 222, 226, 230, 232, and 233-237; (d) a variable light chain complementarity determining region 1 (VL CDR1) comprising the amino acid sequence of SEQ ID NO: 209; (e) a variable light chain complementarity determining region 2 (VL CDR2) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 210, 215, 219, 223, and 227; and (f) a variable light chain complementarity determining region 3 (VL CDR3) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 211, 216, 220, 224, and 228; (ii) the AB comprises a VL CDR1 sequence comprising RASQSISSYLN (SEQ ID NO: 209); a VL CDR2 sequence comprising AASSLQS (SEQ ID NO: 215); a VL CDR3 sequence comprising DNGYPST (SEQ ID NO: 228); a VH CDR1 sequence comprising SYAMS (SEQ ID NO: 212); a VH CDR2 sequence comprising SSIWRNGIVTVYADS (SEQ ID NO: 246); and a VH CDR3 sequence comprising WSAAFDY (SEQ ID NO: 235); (iii) the AB comprises a variable heavy chain (VH) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 46, 48, 50, 52, 54, and 56, and a variable light chain (VL) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 12 and SEQ ID NO: 58; and (iv) the AB comprises a variable heavy chain (VH) comprising the amino acid sequence of SEQ ID NO: 46 and a variable light chain (VL) comprising the amino acid sequence of SEQ ID NO: 58, or a VH comprising the amino acid sequence of SEQ ID NO: 46 and a VL comprising the amino acid sequence of SEQ ID NO:
 12. 29.-31. (canceled)
 32. The activatable antibody of claim 2, wherein the MM has one or more of the following characteristics selected from the group consisting of: (i) the MM has a dissociation constant for binding to the AB that is greater than the dissociation constant of the AB to PDL1; (ii) the MM does not interfere or compete with the AB for binding to PDL1 when the activatable antibody is in a cleaved state; (iii) the MM is a polypeptide of no more than 40 amino acids in length; (iv) the MM polypeptide sequence is different from that of human PDL1; (v) the MM polypeptide sequence is no more than 50% identical to any natural binding partner of the AB; (vi) the MM polypeptide sequence is no more than 25% identical to any natural binding partner of the AB; and (vii) the MM comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 59-81, 208, and
 426. 33.-38. (canceled)
 39. The activatable antibody of claim 2, wherein the CM has one or more of the following characteristics selected from the group consisting of: (i) the CM is a substrate for a protease that is active in diseased tissue; (ii) the CM comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 338-394, and 435-445, 883-921, 1009, and 1010; and (iii) the CM comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 377-394, 883-921, 1009, and
 1010. 40.-41. (canceled)
 42. The activatable antibody of claim 2, wherein the antigen binding fragment thereof is selected from the group consisting of a Fab fragment, a F(ab′)2 fragment, a scFv, a scAb, a dAb, a single domain heavy chain antibody, and a single domain light chain antibody.
 43. The activatable antibody of claim 2, wherein the AB is linked to the CM.
 44. The activatable antibody of claim 43, wherein the AB is linked directly to the CM.
 45. The activatable antibody of claim 43, wherein the AB is linked to the CM via a linking peptide.
 46. The activatable antibody of claim 2, wherein the MM is linked to the CM such that the activatable antibody in an uncleaved state comprises the structural arrangement from N-terminus to C-terminus as follows: MM-CM-AB or AB-CM-MM.
 47. The activatable antibody of claim 46, wherein the activatable antibody comprises a linking peptide between the MM and the CM, a linking peptide between the CM and the AB, or both a linking peptide between the MM and the CM and a linking peptide between the CM and the AB.
 48. (canceled)
 49. The activatable antibody of claim 46, wherein the activatable antibody comprises a first linking peptide (LP1) and a second linking peptide (LP2), and wherein the activatable antibody in the uncleaved state has the structural arrangement from N-terminus to C-terminus as follows: MM-LP1-CM-LP2-AB or AB-LP2-CM-LP1-MM.
 50. The activatable antibody of claim 49, wherein the two linking peptides need not be identical to each other.
 51. The activatable antibody of claim 49, wherein each of LP and LP2 is a peptide of about 1 to 20 amino acids in length.
 52. The activatable antibody of claim 2, comprising an amino acid sequence selected from the group consisting of: (i) an amino acid sequence selected from the group consisting of SEQ ID NOs: 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, and 157, 931, 933, 935, 937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985, 987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005, and 1144-1191, 1200, and 1201; (ii) an amino acid sequence selected from the group consisting of SEQ ID NOs: 931, 933, 935, 937, 939, 941, 943, 945, 947, 949, 951, 953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983, 985, 987, 989, 991, 993, 995, 997, 999, 1001, 1003, 1005, 1145, 1147, 1149, 1151, 1153, 1155, 1157, 1159, 1161, 1163, 1165, 1167, 1169, 1171, 1173, 1175, 1177, 1179, 1181, 1183, 1185, 1187, 1189, 1191, and 1201; (iii) the amino acid sequence of SEQ ID NO: 428; (iv) the amino acid sequence of SEQ ID NO: 1008; and (v) an amino acid sequence selected from the group consisting of SEQ ID NO: 430, 432, 434, and
 1202. 53.-55. (canceled)
 56. A conjugated activatable antibody comprising the activatable antibody of claim 2 conjugated to an agent.
 57. The conjugated activatable antibody of claim 56, wherein the agent has one or more of the following characteristics selected from the group consisting of: (i) the agent is a toxin or fragment thereof; (ii) the agent is a microtubule inhibitor; (iii) the agent is a nucleic acid damaging agent; (iv) the agent is a dolastatin or a derivative thereof; (v) the agent is an auristatin or a derivative thereof; (vi) the agent is a maytansinoid or a derivative thereof; (vii) the agent is a duocarmycin or a derivative thereof; (viii) the agent is a calicheamicin or a derivative thereof; (ix) the agent is auristatin E or a derivative thereof; (x) the agent is monomethyl auristatin E (MMAE); (xi) the agent is monomethyl auristatin D (MMAD); (xii) the agent is DM1; (xiii) the agent is DM4; (xiv) the agent is a detectable moiety; (xv) the agent is a diagnostic agent; (xvi) the agent is conjugated to the antibody via a linker; (xvii) the agent is conjugated to the antibody via a cleavable linker; and (xviii) the agent is conjugated to the antibody via a non-cleavable linker. 58.-69. (canceled)
 70. A pharmaceutical composition comprising the activatable antibody of claim 2 and a carrier.
 71. The pharmaceutical composition of claim 70 comprising an additional agent.
 72. The pharmaceutical composition of claim 71, wherein the additional agent is a therapeutic agent.
 73. An isolated nucleic acid molecule encoding the activatable antibody of claim
 2. 74. A vector comprising the isolated nucleic acid molecule of claim
 73. 75. A method of producing an activatable antibody by culturing a cell under conditions that lead to expression of the activatable antibody, wherein the cell comprises the nucleic acid molecule of claim
 73. 76. A method of manufacturing an activatable antibody that, in an activated state, binds to PDL1, the method comprising: (a) culturing a cell comprising a nucleic acid construct that encodes the activatable antibody under conditions that lead to expression of the activatable antibody of claim 2; and (b) recovering the activatable antibody.
 77. A method of reducing PDL1 activity comprising administering an effective amount of the activatable antibody of claim 2 to a subject in need thereof.
 78. A method of blocking binding of a natural ligand to PDL1 comprising administering an effective amount of the activatable antibody of claim 2 to a subject in need thereof.
 79. A method of treating, alleviating a symptom of, or delaying the progression of a PDL1-mediated disorder or disease comprising administering a therapeutically effective amount of the activatable antibody of claim 2 to a subject in need thereof.
 80. The method of claim 79, wherein the PDL1-mediated disorder or disease is cancer.
 81. The method of claim 80, wherein the cancer is a bladder cancer, a bone cancer, a breast cancer, a carcinoid, a cervical cancer, a colon cancer, an endometrial cancer, a glioma, a head and neck cancer, a liver cancer, a lung cancer, a lymphoma, a melanoma, an ovarian cancer, a pancreatic cancer, a prostate cancer, a renal cancer, a sarcoma, a skin cancer, a stomach cancer, a testis cancer, a thyroid cancer, a urogenital cancer, or a urothelial cancer.
 82. The method of claim 80, wherein the cancer is selected from the group consisting of melanoma (MEL), renal cell carcinoma (RCC), squamous non-small cell lung cancer (NSCLC), non-squamous NSCLC, colorectal cancer (CRC), castration-resistant prostate cancer (CRPC), hepatocellular carcinoma (HCC), squamous cell carcinoma of the head and neck, carcinomas of the esophagus, ovary, gastrointestinal tract and breast, or a hematologic malignancy such as multiple myeloma, B-cell lymphoma, T-cell lymphoma, Hodgkin's lymphoma/primary mediastinal B-cell lymphoma, and chronic myelogenous leukemia.
 83. The method of claim 79, wherein the method comprises administering an additional agent.
 84. The method of claim 83, wherein the additional agent is a therapeutic agent.
 85. The antibody of claim 1, wherein the antibody has one or more of the following characteristics selected from the group consisting of: (i) the antibody comprises: (a) a variable heavy chain complementarity determining region 1 (VH CDR1) comprising the amino acid sequence of SEQ ID NO: 212; (b) a variable heavy chain complementarity determining region 2 (VH CDR2) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 213, 217, 221, 225, 229, 231, and 238-247; (c) a variable heavy chain complementarity determining region 3 (VH CDR3) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 214, 218, 222, 226, 230, 232, and 233-237; (d) a variable light chain complementarity determining region 1 (VL CDR1) comprising the amino acid sequence of SEQ ID NO: 209; (e) a variable light chain complementarity determining region 2 (VL CDR2) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 210, 215, 219, 223, and 227; and (f) a variable light chain complementarity determining region 3 (VL CDR3) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 211, 216, 220, 224, and
 228. (ii) the antibody comprises a VL CDR1 sequence comprising RASQSISSYLN (SEQ ID NO: 209); a VL CDR2 sequence comprising AASSLQS (SEQ ID NO: 215); a VL CDR3 sequence comprising DNGYPST (SEQ ID NO: 228); a VH CDR1 sequence comprising SYAMS (SEQ ID NO: 212); a VH CDR2 sequence comprising SSIWRNGIVTVYADS (SEQ ID NO: 246); and a VH CDR3 sequence comprising WSAAFDY (SEQ ID NO: 235); (iii) the antibody comprises a variable heavy chain (VH) comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 46, 48, 50, 52, 54, and 56, and a variable light chain (VL) comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 12 and SEQ ID NO: 58; and (iv) the antibody comprises a variable heavy chain (VH) comprising the amino acid sequence of SEQ ID NO: 46 and a variable light chain (VL) comprising the amino acid sequence of SEQ ID NO: 58, or a VH comprising the amino acid sequence of SEQ ID NO: 46 and a VL comprising the amino acid sequence of SEQ ID NO:
 12. 86. An isolated nucleic acid molecule encoding the antibody of claim
 1. 87. A vector comprising the isolated nucleic acid molecule of claim
 86. 88. The isolated antibody of claim 1, wherein the AB specifically binds to mammalian PDL1 with a dissociation constant of (a) 0.01 nM to 1 nM, 0.05 nM to 1 nM, 0.1 nM to 1 nM, 0.2 nM to 1 nM, 0.3 nM to 1 nM, 0.4 nM to 1 nM, 0.5 nM to 1 nM, 0.75 nM to 1 nM, (b) 0.01 nM to 0.75 nM, 0.05 nM to 0.75 nM, 0.1 nM to 0.75 nM, 0.2 nM to 0.75 nM, 0.3 nM to 0.75 nM, 0.4 nM to 0.75 nM, 0.5 nM to 0.75 nM, (c) 0.01 nM to 0.5 nM, 0.05 nM to 0.5 nM, 0.1 nM to 0.5 nM, 0.2 nM to 0.5 nM, 0.3 nM to 0.5 nM, 0.4 nM to 0.5 nM, (d) 0.01 nM to 0.4 nM, 0.05 nM to 0.4 nM, 0.1 nM to 0.4 nM, 0.2 nM to 0.4 nM, 0.3 nM to 0.4 nM, (e) 0.01 nM to 0.3 nM, 0.05 nM to 0.3 nM, 0.1 nM to 0.3 nM, 0.2 nM to 0.3 nM, (f) 0.01 nM to 0.2 nM, 0.05 nM to 0.2 nM, 0.1 nM to 0.2 nM, (g) 0.01 nM to 0.1 nM, 0.05 nM to 0.1 nM, or (h) 0.01 nM to 0.05 nM.
 89. A conjugated antibody comprising the antibody of claim 1 conjugated to an agent.
 90. A method of producing an antibody by culturing a cell under conditions that lead to expression of the antibody, wherein the cell comprises a nucleic acid molecule encoding the antibody of claim
 1. 91. A method of reducing PDL1 activity comprising administering an effective amount of the antibody of claim 1 to a subject in need thereof.
 92. A method of blocking binding of a natural ligand to PDL1 comprising administering an effective amount of the antibody of claim 1 to a subject in need thereof.
 93. A method of treating, alleviating a symptom of, or delaying the progression of a PDL1-mediated disorder or disease comprising administering an effective amount of the antibody of claim 1 to a subject in need thereof.
 94. The activatable antibody of claim 19, wherein the NOD mouse is a female NOD/ShiLtJ mouse substrain.
 95. The activatable antibody of claim 19, wherein the activatable antibody has one or more of the following characteristics selected from the group consisting of: (i) the activatable antibody inhibits the induction of type 1 diabetes in a NOD mouse by at least 3-fold compared to the AB; and (ii) the activatable antibody exhibits a safety margin that is at least a three-fold safety margin relative to the AB. 